Convince me I don’t want an M10?

I think you are looking for a really minimal shell only?
If not you could also consider the Alpha SL, on sale for $259. 2 oz heavier, but with pit zips for extra breathability.

Link

I have no direct experience, but the M10 sure looks like a nice rain jacket. Patagonia makes nice stuff and for a lot of people a more durable 3-layer rain jacket is a better investment as they last much longer for an extra 2oz or so. My main hesitation with the M10 is that the torso cut doesn't look very long. I prefer a decent torso length in a rain jacket to keep things protected when I'm bending over setting up the tent etc. The zip also looks like a #3, which is okay but it'll probably wear out in 3 years if you use it regularly.

Two other 3-layer jackets to consider are:
1) Mountain Hardware Blazar/Quasar. These jackets are also 3-layer and they're 8 or 9oz ea. They are kinda short like the M10 and they're not full zip, but they do have wrist gaiters which are awesome if you're using the jacket in the shoulder seasons. The main appeal here though is that you can find them pretty cheap. I got a like new Quasar for $120. Also MH's Dry Q Elite used in these jackets is actually an eVent membrane with MH's own face fabric so it's supposed to breathe pretty well (relatively speaking).

2) Arcteryx Tecto FL. This is their lightest, simplest 3-layer jacket. It's expensive ($380) although I bought my wife one recently on sale for about $225. I would choose this over the M10. It's a bit heavier (9.9oz) but it's got a longer torso cut which I value, and it's more durable (30D fabric vs. 15D, larger toothed main zip rather than a small #3 coil zip). It also uses Gore-Tex Pro shell which I believe is better than H2No.

Not everyone can justify 9.9oz for a rain jacket, but if you use one a lot then it can be weight well spent. The Tecto FL makes very good use of that weight, as it's almost entirely in the quality materials (fabric and main zip) and not in bells and whistles. It seems like the best PNW jacket and it's durable enough to use regularly year round for many years.

Regarding the other jackets you mention, I'd start by deciding between 3-layer and 2.5 layer designs. 3-layer jackets protect the membrane better (ie. no bubbling or wearing through) so they tend to last a lot longer. 2.5 layer jackets are lighter and pack smaller, so they're better if your rain jacket sits in the pack 90% of the time.

In the world of 2.5 layer jackets, I'm not an expert but I like the Westcomb Focus LT because it uses eVent and has a nice long cut which is so nice to have in a rain jacket.

Arc'teryx Alpha FL – Don't get this. The Tecto FL is better: lighter and less expensive.
Haglofs Gram Comp Pull – The old Ozo from Haglofs was better, but this jacket is light and could be great if it fits well.
Montane Spektr – Yeah kinda heavy for what you get. Lighter eVent shells are coming in a year or so (see Outdoor Retailer show recently). BPL said this jacket leaks, but I'm willing to say that may have been an isolated problem because eVent is normally great. A brim would be nice.

I think it depends on your usage. If wearing it a lot, breathability becomes more important than weight to me. If you mostly have it in your pack in case it rains, then weight becomes more important. I just picked up an event jacket I likea lot because I seea lot of rain If I was mostly packing it, I would consider something light like a zpacks jacket.

I'd also recommend the ZPacks jacket, if you're just using it for backpacking. The ZPacks jacket is:

– lighter by about 3 oz
– costs the same as an on-sale M10 ($260 on backcountry.com when I bought mine early this month)
– will remain breathable forever since there's no DWR to wear off
– has a better hood

The M10 seems like it'd be a better jacket for anything where you need a pocket on the jacket and a helmet-compatible hood. I have one and the 3L H2No seems to be really breathable. I've only had it for about a week so don't have much experience with it yet but from doing some "shower tests" and walking around in it I like it a lot so far! It feels nice against your skin, too, better IMO than 3L goretex or event. Some people say the jacket is short, but for me a size large was plenty long and I'm 5'11". The only thing I don't like much is the hood. It just has one adjustment on the back and a relatively short brim. I like ZPacks' hood a lot more. I've also loved the hoods on the two Arcteryx jackets I've used. But the hood on the M10 is probably "good enough".

If your primary reason for switching is more breath ability, I'd caution you to have low expectations. I have two rain coats, a light PU coated one with poor breathability by the specs, and a Gore-Tex 3L pro shell one (Alpha LT). It's hard to tell much if any difference in breathability in practice. They're both sweaty. The main difference is improved durability in the 3L jacket (e.g. it lasts longer than a season without delaminating) and more features for about 2x the weight. But in a blind test I doubt I could tell the difference in moisture transport. Since you're talking about two very similar membranes (2.5 vs 3L H2No) I doubt you'll see much difference.

Thanks guys – a range of quality comments :)

Dan – Good pick-up on the Tecto, no idea how I missed that one… seems like a good balance between rainshell and hardshell in terms of materials (durability) and weight. Not the best on either count, but a good all rounder, and active shell should be nice. Bicep pocket a bit odd and would prefer napoleon, but that's ok… Strange lack of reviews, all the attention seems to be on the more flagship (I guess) Alpha FL, but you're right that it's not really the preferred option for backpacking (vs climbing).

Soooo, I found one in a medium, nice green for only $240 at Basegear… so I just bought it :) pretty psyched!

Addressing other points for anyone reading in future –

M10 torso cut – agreed, patagonia rain jackets are cut too short. This is not a concern while walking… but bending over to put in tent pegs while not wearing rain pants is a great way to get wet shorts. 'Hip length' cut on the dead birds jacket should be nicer… also longer sleeves :) and a proper slim fit…

MH Blazar / Quasar – OutdoorGearLab absolutely slammed these for durability. Noted, they were climbing in them and being a lot harder on them than I would… but I think they said one started delaminating after one wash? Too risky for me…

Spektr – agreed, I reckon BPL might have been overly harsh.. I wasn't worried about the leaking though as much as the weird closure. Hood also a bit sub standard.

Zpacks – Great in the pack, but I have my doubts about cuben for clothing for extended periods for both breathability and durability reasons. Don't get me wrong, I love cuben for tents and stuff sacks, but I don't want something I have to baby… also 'around town' usefulness is effectively zero. When I'm on a holiday and staying at a backpackers before setting off I don't want to look like I'm cleaning up chemical spills :D

Re step up in breathability – yeah I know this won't be life changing and I'll still be packing my houdini and using as much as possible, but I'm just hoping for a bit more enjoyment (while losing some weight). The 2.5 just feels awful anywhere it's touching your skin once the humidity rises. I like short sleeved base layers occasionally and it just gets gross on your forearms… extra layer of fabric should be nicer.

Sounds like a great buy. Let us know how it goes.

Regarding the Quasar, as I recall it was the hang tag that came off in the wash. I don't think the actual main fabrics were coming apart. The hang tag is affixed via an extra patch of fabric that is sorta ironed on inside the jacket. It's true this patch isn't on very well. I actually just pulled/cut this patch off mine to drop a few grams.

In any case, the Tecto is the better jacket. The Quasar might win for membrane (eVent supposedly) but the Tecto is longer and more durable. The Quasar isn't beefy by any means, the shell fabric is similar to most 6-7oz rain shells and the membrane is better protected because of the 3rd layer. Of course the Tecto is more durable still because they put the weight into the fabric rather than features. The Quasar has a restrictive hood and the torso cut is kinda odd in addition to being short. I'm happy with mine but it's certainly not the greatest jacket. I agree a napolean pocket would be better than an arm pocket for the Tecto.

For many years my solution WAS a Cabela's GTX PacLite parka & pants. "OK" but barely in terms of breathability.

Now I have REI's Kimtah eVent parka and pants and love them. Got both on 20% off sales and found they were the least expensive eVent garments around.

Lachlan,
Just got one for Xmas, so don't know how well it will perform yet. They are selling for over a hundred $ off as we expected.
Did run some water on it, and the DWR is tops, much better then RAB Pertex Shield. Only time will tell how durable it is – whether the D is in the DWR.
Got an XL to get it longer. A little bagginess around the torso is no problem, because under the pack, hipbelt and straps, it is kept from flapping about. (You can cinch up the bottom hem with a shockcord.) But was surprised at how tight the sleeves were. In this cut, Ahhnold could definitely not wear this jacket, in any size.

If the DWR holds up and it breathes better, it will replace an older Patagonia Specter pullover. The texture of the inner is more of a knit than the slick surface of the so-called 2.5 WPB urethane coated jackets that are the least breathable, although the Specter is the least worst of what I've worn of that type. So I'm optimistic.
But you might want to look at the new one from Montane that is shown on a recent outdoor show thread on this forum. A little heavier, but not by much. And very nice looking. You might have to wait a while for one, though.