Recommendations for down jacket

I think you had better target the inches of loft for a down jacket, and not worry so much about 600 versus 900 fill power or fill weight.

If the 900 jacket has been compressed too much, then it will feel like it is empty.

Everybody is different. I hike in a thin long sleeve shirt. Then in camp, I pull on a thicker polyester fleece shirt. When it gets cold in the morning, I pull on a Mont Bell down inner jacket (which is pretty flimsy) and a silnylon rain parka shell. If the temperature got below +20*F, I would be uncomfortable.

–B.G.–

Which 900 fill jacket did you have?

It was this jacket:

http://www.montbell.us/products/disp.php?p_id=2301344

EX LIGHT DOWN JACKET MEN'S

… though. I imagine, if I just want it 30% more warmth, I'll just get 30% more fill weight :-P

It is primarily, but not exclusively, the down loft that will get you warmth. More fill weight just gets you more ounces.

Sewn through construction is particularly bad about getting compressed.

–B.G.–

Kevin, the Montbell Mirage (12+ oz) is the best UL down jacket I have ever owned. I have the 9 oz MB parka and there is no comparison at all in warmth. Probably about as high a percentage weight in down as it gets. Box baffles. Unless I am worried about being TOO warm, I will be taking that and somehow work it into my sleep system if I feel the petty need to undue the exta 3 oz. Probably pretty perfect for the Sierra in shoulder seasons. I like being warm. Pricey though. But should last for decades if taken care of.

I bet something with 3-4 oz of high loft down would do you better. That Ex lite also doesn't have a hem, so heat can escape that way.
This is a good deal and pretty light:
http://www.montbell.us/products/disp.php?cat_id=70&p_id=2301174

This jacket would keep me very cozy at 32 and I think its the warmest thing in its weight class: http://www.montbell.us/products/disp.php?p_id=2301365
5.3 oz of down 12.8 oz total

That said, depending on your backpacking style (how much walking you'll be doing vs. hanging out at camp) people often go with less for the same conditions. My main insulation for the warmer 6 months of the year has been a rab xenon 60gram synthetic jacket. At 32, I'd be a little chilly for long hours at camp, but I'll either hop in my sleeping bag or keep hiking if its too cold for the jacket.

No shortage of choices, here's a couple more good ones with varying prices: western mountaineering hooded flash jacket, patagonia ultralight hoody, golite bitteroot, rab continuum

edit: just posted and saw mark's comment. I've only tried it on, but the mirage definitely seems to stand above the others for pure warmth/weight.
http://www.outdoorgearlab.com/Down-Jacket-Reviews/MontBell-Mirage-Parka

LOL Did our posts just pass in the mail?

Its a sign Kevin!

I'd be careful not to jump from one extreme to the other. The Ex-Light has 1.8oz of down, while Montbell's Mirage has 5.3oz as mentioned. That's a huge difference. If you're going to err, it's nice to be the on the side of too warm but there are downsides as well with opting for an excessively warm jacket (bulkier, heavier, might be too much to sleep wearing, unequal insulation (way more insulation for the upper body vs. the lower)).

I recently owned an Ex-light vest and Montbell's Alpine Light Down Parka (similar to the Mirage but less down (4.3oz) and heavier fabrics). With that setup I felt like the vest was good for the warmest month of the year, and the Down parka was good for the shoulder seasons, but I didn't have a good general 3-season jacket. The Mirage is even warmer than the Alpine Light Parka. It's going to feel a bit ridiculous having that along May-Sept in most circumstances.

I suggest looking at something with 2.5-4oz of down. Keep in mind 2.5oz of down is already 50% warmer than your Ex-light, while 3.5oz is about twice as warm. That's a pretty nice way to go. There are a number of nice 3 to 3.5oz down jackets with a total weight around 9-10oz, such as the Western Mountaineering Flash, Montbell Guide Parka, Arcteryx Cerium LT and Patagonia Ultralight Down Hoody – the latter two of which are even lighter if you go no hood (not recommended).

FWIW, the Patagonia Ultralight Down Hoody can be had 40% off right now (see Gear Deals section) or the Arcteryx is $100 off here:
http://www.basegear.com/arcteryx-cerium-lt-hoody-f13.html

@ Mark
Yes, the spirit of the internet has spoken, and it says: Mirage.

…but seriously, what Dan said rings true for me. I think for a three season down jacket, something like the pat UL hoody, WM Flash or arc cerium hoody is ideal. The mirage is definitely the next step up in warmth (but tempting for only 3 extra oz!)

That rab deal is indeed quit nice.

Dan, well said.

No, I wouldn't bring the mirage in mid summer in the sierra. If you want a good September – October (those and Early June are my favorite times) jacket though it might be pretty sweet. Like I said somewhere else, it tempts you since the issue of weight and packing bulk is almost nil in this case, you are not going to be paying much of a price there. Um.. yeah, "price" maybe not a good word to use in this case. LOL

The rab looks pretty sweet at that price, it will be the same bulk and weight as the mirage but less warm, and a lot cheaper.

However, there is a thing called a zipper that can prevent you from getting too warm in some cases, and a quilt for the legs. Being too hot in the sierra at night would be a new one for me, but I would be (and have been) fine with less too. I'm probably trying to rationalize the luxury.

Anyway, the mirage is just one of those things that is so well designed it tempts you, even though a jacket is not the most efficient way to use the down.

The Mirage is the best sub pound down Parka I have ever seen.

+1 on Dan's $0.02

To get even better feedback, disclose 2 important items:

1- where r u on the warm-body and cold-sleeper spectrum?

2- do you intend to use the jacket as part of your sleep sys in true UL fashion? Or will it b used mostly to 'lounge'?

in the sierra nevada shoulder seasons, lows in the 30-40 range, unless you are a Cold sleeper, sleeping in anything warmer than a "layering" down jacket like the MB UL parka will be overkill.

Instead of "general feedback" u can really dial it in w/ your answers to those.