Arc'teryx Atom SV- review

Me being snug. With some dodgy lens flare.

Fleeces are good at keeping you warm when its cold and there is no wind. However, as soon as a slight breeze begins, it tends to go straight through. Synthetic insulated jackets seem to be the answer to the problem of what to wear when its cold, windy and wet, when a down jacket would wet out too soon and a fleece would be too bulky and not provide any protection against the wind.

My down jacket is great, but standing on a hillside in the driving rain isn't the kindest thing I can do to it, and once wet, its as much use as a paper bag, and all my fleeces from years gone by, although still functional, are an additional weight which I could do without. Ideally I needed a synthetic insulated jacket before I moved up to the Peak District, and I'm very, very glad I bought one.

Synthetic "belay" jackets come in several flavours, with differing amounts of insulation for differing uses on the hill. They range from the super-lightweight Montane Fireball smock, for Mountain Marathons and as a layer that packs down to nothing, through to the ever popular workhorse, the Rab Generator Jacket (though the Atom SV is closer to the Generator Alpine) and the Mountain Equipment Fitzroy.

I decided on the Arc'teryx Atom SV for a number of reasons. Its main purpose was to be in my rucksack, ready to be deployed at a moments notice should we stop for any period of time, but it also needed to be warm enough to throw on over a shirt when going into town, and also, I managed to get it for less than I could get any of the other jackets- in my case an important point. 

Features
As this is a jacket for quick stops, fast warmth and convenience, it needed to be big enough to engulf any jacket I own, yet be streamlined enough to go under any other jacket I own. An interesting conundrum, but the cut of the jacket enables it to do that with ease.
The Atom is made with a silk like face fabric that Arc'teryx calls Luminara Nylon. It has a silky tactile feel and a fantastic DWR coating. It is 20 dernier ripstop, with good weather resistance, and apparently, is very breathable. The jacket itself is not classified as "waterproof" as it doesn't have taped seams, however, standing in the rain for a while is not an issue at all, as the water beads fantastically well, and sheds like a ducks back. (cliched I know, but its the only way to really describe it).

Lycra cuffs. Comfortable. Sleek. Convenient.

The inside fabric is, again, Luminara Nylon and it feels really very silky. Not something that you tend to say about fabrics on outdoor jackets. Wearing it into town just over a t-shirt is fine, and the lycra wrist cuffs are brilliant. I was never a fan of jackets without adjustable wrist cuffs, but recently there seem to be better ways of fastening around the wrist. The Atom is perhaps one of the most comfortable that I have come across.

Internal Pocket

It has 2 hand warmer pockets and an internal storage pocket that is pretty damn big, the hand warmer pockets have one side of them made with the Luminara Nylon and have the front side covered with fleece, so you get warmth and comfort at the same time. Mmmmm.

The tail of the Atom comes down a fair way and keeps your bum warm- quite an important point, you might agree, if you have ever been on a hill with a cold bum.
Also, you can roll the whole thing up into its own hood. Great to have a small package just on top of the sack to shake out and stick on at a moments notice. You can crush it down smaller, we've even managed to get it into a 1litre waterproof bag... but I've never had the need to when going on the hill.

The hood itself is easily big enough to accomodate a small helmet (we're talking petzl elios type thing), and it has a volume adjuster as well, so that if you aren't wearing a helmet, it doesn't blow about too much.
As I mentioned, the fabric is silky smooth, however, I'm not sure how bombproof it would be if you started to scrape it up and down granite slabs. It might be fine, but as soon as the going gets gnarly, I'd tend to take it off and stow it in the sack, or wear it as a mid layer with a more robust jacket over the top.

Fleecy cheek pad, and annoying internal drawcord

A lot of thought has gone into what can make this jacket comfortable. The baffle around the mouth and cheeks when the hood is done up is covered over with light fleece and there is a small lycra flap across the back of the neck to prevent drafts from wafting down your neck. Nice little touches that show a well thought out bit of clothing.

Insulation
The Atoms are insulated with Coreloft, Arc'teryx's version of primaloft. It is made with 100% polyester and is a lightweight and thermally efficient polyester staple fiber insulation.
Arcteryx says "Core Loft is constructed of a double strand of continuous polyester filaments. The finer yarns (1 denier) are "crimped" to help trap air molecules which in turn help trap body heat while the larger yarns (3.5 Denier) provide loft and resilience from compression. The fibres are siliconized to help add resistance to moisture and decrease drying time."
Yes, the jacket dries fast, I can attest to that, and the fabric appears to be breathable to a point, I certainly wouldn't go running in it, and its not really a noticable trait as you sit around getting warm on a hill.

To be totally honest, as far as I can tell if it is warmer than primaloft of the same weight, it is marginal. I'd love to give a comparison with drying times, but don't have a primaloft jacket to compare it to.


Issues
Yes, every jacket has its good points, but they also have their bad points.
The Atom has relatively few, but they are worth mentioning.

This happens EVERY time

The zip, designed to be easy opening- so that you can just pull the open part of the jacket and the zip undoes- works well. Too well. If you are sitting around, or even moving slightly, and the zip is not done all the way to the top it has a very annoying tendency to creep down until the jacket is gaping open. On a short walk through the fields the other day, despite the fact the zip was done up to the top, it kep creeping down. Every 3 or 4 minutes I had to re-zip it up to the top. Not a deal breaker, but a bit annoying.

The thing which is most annoying is the the toggles to cinch down the hood are on the inside of the jacket. Yes, it may make the outside of the jacket look sleek and snazzy, however, there is a minor issue in practice. Imagine you are sitting there in a rain/snow storm and it starts coming in through the hood. You want to close it up. You have to undo the jacket, fumble around inside the top for the drawcords (probably dispensing liberal amounts of snow/rain inside the jacket at the same time), pull them tight, and then do up the zip again. However, now, when you do the zip up, the cords don't sit down nicely inside the jacket, nope, they get caught up and stick out the top, and generally go up your nose. Really annoying.

Adjusting the hood. Thankfully not in a blizzard

Differences
Looking at the Atom SV vs the LT- The SV, as I mentioned has a hood, where as the lighter version- the LT, does not. The other major difference is that the SV has insulation all the way around the body. It is windproof throughout, and once zipped into it, with the hood up, it is like a cocoon. Fantastic, as long as you aren't about to suddenly break into serious amounts of exercise. You'll need to take it off soon enough, unless its ridiculously cold.
The LT on the other hand has underarm panels that are made of stretch fleece. not windproof, but they do let the jacket breathe a bit more, and may be a little more practical should you be using it to keep you warm as you participate in activity.


Overall
No, this isn't a jacket for hyperlightweight fiends, and people who want a slightly warmer layer to stick in a small sack for a Mountain Marathon. It's just a bit too heavy for that. As a belay jacket for a climber, yes, this would be a great jacket to throw on in a very cold place. Maybe a little too feature rich for someone on the higher end, if you are likely to be sitting on a belay for quite a long time as your partner hacks about above you, yes, this is a good jacket.

All packed up and ready to rock

I have used this in various situations of high demand, carrying things on and off hills, and then spending quite a while sitting and waiting in cold, wet, nasty conditions, before carrying other things back off hills, I've used it as a top layer and a mid layer, and I've used it for wandering down into town.

How I would improve it
Looking at the other options, I prefer aspects of other jackets, but I also prefer specific things about the Atom.
If I could have an insulated jacket with the cuffs and pockets of the Atom, with the hood pullcords on the outside, and a zip that didn't unfasten as you walked along/ sat still, it'd be pretty much perfect.

I can honestly say that despite its faults, this is pretty much the most used jacket for general hill walking, cragging and day to day life that I own. If I was going to pack a rucksack to take with me onto the hill right now, it'd be one of the first things on the pile.

The perfect jacket for hurrying up and waiting.