Do it all pad combo

Sounds reasonable, the big question is whether you will be comfortable on just a Ridgerest. Lots of people move to inflatable pads from closed cell foam only because it is more comfortable. But that is a personal thing, and you will need to try it out. Personally, I used to use a couple closed cell foam pads (sandwiched) and it worked just fine about 70% of the time. The other 30%, unfortunately (when the sleeping spot was less than ideal) was pretty rough. Fortunately, I switched over to an inflatable right when the NeoAir came out, which meant that I didn't have to pay much of a weight penalty.

You might consider a very thin closed cell pad to put under the NeoAir. The all-season would provide plenty of warmth, and the thin closed cell pad will provide protection for the NeoAir (which is why I assume you don't just use the NeoAir in the summer). With a super warm pad, you might be able to get by with a sleeping bag/quilt that is just a little bit lighter.

Yeah the ridgerest comfort is a potential dealbreaker, but at least finding out won't be very expensive. So many prior threads talk about layering a CC pad on top of an air one that it seems to be a well-accepted and effective system. A very thin foam sheet below the neoair sounds like a good preventative measure.

You don't really need more than R5/R6 for 4 seasons. R7 is overkill. Snow insulates.

I like the Nemo Zor short (R2.5, 9.1oz), coupled with a 1/8" Evarest pad (R0.75, 3oz). Use a 1/4" pad (R1.5, 6oz) for shoulder season, and a 1/2" pad (R3, 13oz) for winter.

All pads are trimmed as necessary. Pack an extra 2oz GG sitpad (R2.2) for the feet if you find it necessary. I don't – I can usually find 'stuff' to put underneath.

Affordable and combines the good warmth-to-weight ratio of closed cell foam and the comfort of an inflatable, all at a very good weight.

Why not just get an XTherm? Weighs less than the All Season and has a higher r-value. My son (who will snow camp with me) outgrew his IAC so I gave him a regular XTherm as an all-year pad.

Part of it depends on where you hike as to durability questions but I am a fan of a two pad system both for warmth and puncture resistance my thoughts on it here:

http://40yearsofwalking.wordpress.com/2010/08/30/current-thoughts-on-sleeping-pads/

i'd second the suggestion to get an xtherm if you aren't already invested. Its a simpler system then combining various pads and it allows you to bring less insulation during the warmer seasons. I used a 40 degree quilt from May through october in the CO high country last year with an xtherm. I used a thin CCF pad in place of a groundsheet, to protect the xtherm and provide a frame in my pack. That xtherm is pretty spaceagy. Nothing comes close warmth/oz.

I have an unusual arrangement.
I don't know how it would do in very cold climates because I am in the Southeast, and it normally doesn't go much below 20*F here, unless we get a somewhat rare artic cold snap that can get down to almost zero. That's not real common, but once every 5 years or so it may happen.

Anyway, I use a Klymit X-Lite 3/4 pad inside my sleeping bag, and put a 3/16" CCF pad under the bag, with a HeetSheets reflective ground sheet under the CCF pad, as a ground sheet. I use my Klymit inflatable vest to put under my legs, also inside my sleeping bag.

These Klymit things are only about 1.5" thick, so they fit in my WM Alpinlite bag pretty easily.
They have the "loft pockets, which trap air and also allow the sleeping bag to get some loft underneath me. And the pads don't suffer from being exposed to the cold outside air because they are inside the bag with me and actually get heated by me.

The CCF is for under the whole thing, outside the bag, and helps protect the bottom of my bag while also providing some added insulation from the ground. And emergency insulation if the inflatables should fail.

The HeetSheets ground sheet simply helps to reflect some/any of the heat that might have made it that far towards the ground. So, I try to minimize the heat that can be pulled out of my sleep gear by the ground as much as I can, with various layers and technologies that hopefully will complement each other and work to do that.
And it serves as my ground sheet to keep water away and keep the rest of the gear clean.

Very light. The Klymit X-Frame Lite 3/4 pad is only abourt 6.5 oz. The vest is my body insulation during the day anyway, and doesn't fail when wet, doesn't lose loft(unless it's punctured) can adjust the insulation layer as needed, all the way down to none, and does double duty as the pad under my legs at night.
Weights:
Klymit X-Frame Lite 6.5 oz.
Klymit Vest: 6 ounces(counting only half the weight because it's double-use and takes no room in my pack because I wear it. The other half I count as clothing weight).
CCF pad: 4.5 oz.
HeetSheets ground sheet(trimmed): 2 oz.(which would be needed no matter what pad I use anyway).
Total: 19 oz.

So far, so good.
20*F is presenting no problems.

The best thing about it is low bulk. Each piece(except the CCF pad) packs down very small individually, and stores easily in pockets or in the pack without taking up huge space. So, the low bulk is very attractive, and it allows me to take less of the stuff with me when summer rolls around, but not have to buy a different pad. I just use the Klymit 3/4 pad and a groundsheet.
Don't know about zero temps yet.

Have your cake and eat it too. Use the Neoair all season year round. And add CCF in winter. A good nights sleep is worth a couple of ounces, at least it is for me.

I have been surprised how well even the NeoAir XLite works alone. I have used it down into the teens alone and it was fine. So I figure I'll just use my Xlite NeoAir and for really bitter conditions supplement it with either a cheap blue foam pad or a fancier foam pad.

+1 on the XTherm. It has a 70D bottom instead of the 30D on the XLite, so I feel no need to use a thin foam pad for protection, and at R5.7, your good to go year round.

Also, my XTherm weighs a little less than what my XLite and 1/8" CCF used to. Price wise it's about the same as buying those two together too.

Thanks for all the input so far!

Brian,
There's not always snow where I camp. It can be in the teens and single digits with the ground bare. It's wise not to count on snow. I will check out Nemo pads; they're not a company I had considered before. My main reason for considering the neoair is that the wide width can be trimmed to length, which as far as I know isn't possible with other inflatables.

Raymond,
I was looking at a two-pad combo for modularity. Does your son use the Xtherm by itself as his year-round pad?

Serge,
If I could indeed use a lighter bag and be as warm, the Xtherm would probably be worth the investment. Something to consider, thanks.

Greg,
Good point! Also applicable to the Xtherm, I suppose.

Alex,
Certainly a comprehensive overview! The chart you included is makes clear what an array of offerings Thermarest has had over the years.

Tom,
Sounds like you have everything dialed in for yourself. I dont know what I want to go the Klymit route since I have yet to decide on bags vs quilts. Also, where I hike is often overgrown and full of thorns, even when on the path–I think I'd be worried about an inflatable vest in those conditions.

Yes it is his year-round pad. His sister (who won't go in the snow or cold) now has a regular NeoAir, old-style.

So I ran across an excellent deal on an xtherm and took the plunge. I think it was a good decision; I've only napped on it indoors so far, but comfort-wise it gets an A+. If it's as warm as it's supposed to be (or conversely, as long as I'm not too cold a sleeper), it should be perfect. My question is: how important is it to use the inflator bag? It's much easier and faster to blow up by mouth.

I just took my XTherm on snow in below zero temps. Worked like a champ.

Thermarest says that moisture buildup on the inside wont hurt the pad. Just store it with the valve open and uncompressed.

And yes, the inflator bag blows. No pun intended.

Exped UL7 and if needed add a thin foam mat.

NeoAir Z-Lite Sol > Ridgerest.

(one liner about some sleeping pad without further explanation or reasoning b/c my opinion is gold even if it's not related to OP's question.)

C'mon guys. Seriously….

+1

:)

Especially when the OP says that he got his pad so input no longer needed…

My current pad is a BA Insulated Air Core, long (24oz). I'm 6'2" so I could get away with an XTherm regular (which would actually work better with my quilt I think), which at 15oz, would save me 9oz. My wife could use the medium, and save her even more.

But they are so freaking expensive! Is there any point in waiting for a deal, or am I about to drop $360 on sleeping pads?

Depends on how bad you want it. By the time I get to making a forum post I've generally been thinking about a purchase for months and watching prices during that time, so I have a good idea of what's the best price I'm likely to find and just wait for it to happen. Campmor gets cosmetically irregular Therm-a-rests from time to time that sell for big discounts (~30% off IIRC). I was going to wait for one of those sales but found one on ebay last week that was within what I was willing to pay, so I snapped it up. There's no getting around that such big ticket items are an investment, but if you're able to watch and wait, you can minimize the damage to your wallet.

I didn't know about the campmor sales. I'll start keeping an eye out.

I might also but only a medium first, and see if I can handle having the pad be 6" too short for me. If not, it'll become my wife's pad, and if so, I can save a little extra weight by getting myself another medium instead of a regular.

Thanks. Good to hear a positive report from a night at those temps. I know there's been some debate on the moisture issue but didn't realize Cascade Designs had directly said mouth inflation was okay. Bueno!

Good plan. I actually bought a large for the width and will be trimming it after I get some nights on it and decide how short is short enough.