I own an Arcteryx Cerium LT and I absolutely love it as a midlayer, or outer layer in dry conditions, but when it's super cold, windy, and snowy/rainy this is the jacket I grab! It packs down decently small, keeps you super warm, and will absolutely keep you dry. I agree with a couple other reviewers saying that it's too warm. I wouldn't use this as a jacket if I'm being active (hiking/skiing/snowshoeing/etc) unless it was super cold, I would instead opt for a waterproof shell and insulated jacket that I can easily dump heat with. I am a skinnier guy, and my only complaint is that the sleeves are not quiiite as long as I'd like, they still fit but are right on the cusp of being too short, and I also think the fit could be made slimmer. You don't need to wear many layers underneath this.

Purchased this jacket primarily for “street wear”. First real cold Artic blast hitting us the past few days. Single digit sub-0°F days. Jacket wearing a baselayer alone is fine for walking speed effort activity. Bit too warm for shoveling yesterday’s light Lake Effect snowfall. Drop the zipper down and loosen the hem drawstrings to vent. Wish the zipper was a two way unit. Goo thing the cinch grabs are glove friendly. Hydrophobic down and 💦 resistant outer fabric are couple features that pushed me towards this jacket. Doubt if I will ever be wearing this jacket in conditions where the precipitation is rain or rain/snow mix. Bit too warm a coat for those conditions. Still a good thing for the chance of getting caught in rapidly warming, wet situation. Gale force winds and single digits above 0 a few days ago. Seals at cuff, hem and hood made the jacket windproof. Toasty warm walk in double digit below windchill conditions. Handwarmer pockets are functional. Proper design and sized. Insulation on the outside with just the thin inner liner between your paws and torso heat.

Fit for my body size and shape is good. Short at 5’4”, ~130#, 37” chest, 29” waist. Like others have noted the arm pit area is minimal. Testing wearing a baselayer, mid-layer of heavier weight fleece resulted in a “firm” fit. Any tighter would be a restrictive fit.

Summary: Durability? Time will tell. Negatives are lack of a two way zipper and needing a less restrictive cut in the armpit area. Jacket for moderately 🥶 low activity to real 🥶 moderate activity.

I originally purchased a large after reading reviews saying the sleeves were really long, but they weren't quite long enough so I sized up to the XL. The XL fit great in the shoulders and sleeves but the body was far too baggy. Unfortunately, I had already removed the tags and worn it outside, so I am unable to return. As fo rthe performance of the jacket, it is a bit of a unicorn - waterproof shell and a decent down fill had me pretty excited and it is indeed quite warm, but the fit is just not there for me. Bummer.

Waterproof insulated down jacket... Totally was psyched about this product, wanted it to work, spent a LOT of time researching and pulled the trigger.

As mentioned by other reviewers (on this site and others) unfortunately I too think the armholes are cut way too high, so the fit was too tight to work. Upsizing might work for some, didn't work for me.

Also, in the version that I tried (Feb 2018 ) they replaced the down panels in certain areas with schoeller like fabric (makes sense) that wasn't insulated (doesn't make sense) so my arms were freezing in those areas. Other companies put synthetic insulation in those areas. Maybe they fixed that since. The outside fabric felt absolutely bomber, like you'd laugh at the rain. Bummed the fit didn't work out.

Bunch of people also mentioned arm lengths too long. I did not experience that.

Pretty surprising that armhole fit turned out to be the deciding factor coming from an outdoors/climbing type company.... but for me it was.

RAB... Please let me know when you relax the armhole height/fit (across your line) and I'd buy one of these immediately. Insulate everywhere & watch your armhole length.

Shoppers: This might be the jacket for you just beware the fit quirks.

P.S. Ultimately went with the ArcTeryx Thorium Hoody AR (Dec 2018). Wasn't a hood guy, got the hood, now a hood guy. Tshirt underneath works fine in Boston freezing winter temperatures. Cerium LT seemed too light for "the one winter jacket" job, and exterior fabric not as tough or potentially water resistant as the Thorium. Love the Thorium.

My husband had a really good waterproof jacket (HH) but it wasn't insulated. Wanted a down waterproof so he didn't have to wear 20 layers to keep warm. He has had it on since purchase. The other waterproof hasn't seen daylight. It's warm, toasty in fact, no leaks or water seepage on shoulders or zips, roomy, good pockets. Surprised other reviewer says it runs small, rogue size?

I wanted a light and packable, ultra-warm jacket for low-activity winter outings and after doing a lot of research decided on this jacket. Very few jackets offer down insulation and a fully waterproof outer while also being packable and this jacket caught my eye for that reason. I overheat quickly with higher levels of activity and love that I can pack this down and stuff it in my pack to have available for when things slow down or for when temperatures drop. Being able to stuff it down is also great for travel! How often can you pack a winter outer layer into a carry-on and still have room for anything else?

I went for the Rococco/Horizon color and love it. It's somewhere between red and burgundy depending on the lighting and the color isn't obnoxiously loud but still stands out from the usual blacks and navys.

In terms of performance, it has so far lived up to my expectations. With regards to warmth, with the hood up, fully zipped and draw cord cinched up it has easily kept my comfortable into the negatives (F), even without a hat. It has held up well to high winds on a trip to Chicago. I have also had no leaks in the waterproofing during downpours. I also like that it has a resilient outer. Many other packable options feel paper thin and I worry that the slightest brush against something rough will tear the fabric. Not the case with this piece.

A note on size:
I initially purchased a size L based on the sizing chart. A size L is also my usual go to size but I unfortunately hated the fit. I have broad shoulders and an average length torso and this jacket was tight under the arms and across my shoulders and barely extended to my belt line. I personally prefer my winter outer-layer to be a bit on the longer side and not fit like a down sweater. As for the shoulder and chest sizing, it wasn't what I expected and am used to for a size L. Too fitted in the shoulders and chest for a piece that I would want the option to layer with and very tight under the armpits which made it look quite awkward on me. I was pretty disappointed but because I was so excited about the features I decided to return it and purchased an XL instead. I am really happy I gave it another chance! I love the fit and love the jacket. Of note, I recently bought a Columbia outer-shell in size medium and it fits about the same as this does in XL. I would definitely recommend sizing up if you are tall and have wide shoulders and large chest.

Pros:
-Very warm
-Waterproof
-Appears as though it will be durable
-Packable with an included stuff-sack

Cons
-Runs small in the shoulders and under the armpits/chest in comparison to other N. American brands.

When I first came across this jacket, I was doing some research about the Rab Neutrino Endurance jacket. I saw this as a suggested review video on youtube and discovered that the shell fabric is seam sealed. This was very attractive to me since I only wear black clothing and usually down leakage is a huge issue for me. The down would fly out of the jacket and cling on to my black clothing and it would be very unsightly when I took the jacket off. I also loved that this jacket has a seamless down box baffle construction with hydrophobic 850 fill power goose down and that it packs into a waterproof sack. I ordered this jacket immediately after seeing the review. The jacket came promptly in two days. I try on the jacket and I instantly felt discomfort at the underarms. The armhole is way too high and the sleeves doesn't lay nicely when worn. I understand the fitting difficulties that come with raglan sleeves, but this was so uncomfortable that it was unacceptable. I will be returning this jacket. Not recommended for fit issues.

Pros:
- Fast shipping
- Very warm. Hydrophobic high 850 fill power goose down
- Durable, waterproof seam sealed shell
- Seamless construction
- Waterproof pack

Cons:
- Uncomfortable fit
- High armhole
- Runs slightly big