I wrote a review on the hoodie version of this jacket, and just bought the jacket version of it. Here is why: I am 5'10" and weight 160 lb. I always wear a size Medium in Arc'teryx. However the Hercules cut is a bit loose and a bit more roomy (without being baggy at all). I found out that getting a size SMALL, was a stroke of good luck. The jacket fits very athletic doing it one size smaller, and the arm length and torso are still perfect. However by having a snugger fit, it keeps body heat more efficiently, and I can use it for layering if I need to. I had originally purchased a Venta AR, in Medium which has a windstopper fabric, but I found that the forearm fit was too loose, and cold air would get in through the wrists. The Venta is not meant to be a bit insulator layer, but it is worthlss if you have cold air moving up and down your sleeves! Also, the neck portion of the Venta was too stiff when zipped all the way up, and the zipper scratched my chin. No problem with the Hercules!!! The high loft fleece feels wonderful against your skin, fits athletically, and I can even wear the size Small Hercules jacket as a layer underneath my Hercules hoodie (M), which I did this weekend at the football stadium! Layered like that it was like a full winter coat! It is not 100% windproof, but it is 95% windproof, and the breathability is SUPERB! Mine is black, so it is quite easy to combine with other garments. I love the fit, and it is warm and super comfortable. It is not as warm as an Easy Rider jacket, but the easy rider is stiffer and way too hot to layer if you are going to be active outside. I love this jacket!!!

I was a bit hesitant to order this jacket based on some of the reviews about the length of the jacket 'and bagginess' around the shoulders, but it turned out to be a non-issue for me. I own several Arc'teryx jackets (Fission AR and SV, Alpha LT) and I have to say this is truly and all around (AR) jacket. It is definitely shorter than the Alpha, it sits exactly below my belt, and the rear drop back covers 3/4 of my rear end. I can see that if you have a longer torso, this jacket would just be too short. If I wear a slightly longer fleece, the front edge will peek underneath the jacket around the belt. The extra room around the shoulder area is great for me. For whatever reason the other jackets like the Theta AR always seem to rub against my armpits and this is just uncomfortable. I do not have this problem with my Beta AR, and I can put a fleece underneath with comfort. The other feature I like is the collar, you can zip it all the way up and it protects your neck from the elements. I think this is an important distinction with the Alpha line. The Alpha design probably assumes that you will have the hood up most of the time. Don't get me wrong, the Alpha LT is probably my favorite jacket for the outdoors, the fabric is super tough and more flexible, and is a little longer overall front and back. The only thing is that the Alpha leaves your neck more exposed if the hood is down. The fabric looks bombproof and the cut is trim. I actually love this about Arc'teryx in general, but this jacket is particularly nice fitting. I am 5'10" and 169 lb, athletic build and I just love how this M size fits me. The hood is very well designed as well, you can custom fit it to perfection with all of the adjustments possible. The Beta AR is significantly nicer that the Beta SL. It is not only a bit longer (about 3/4" longer, and it may not seem like much but it makes a difference), has pit zips, and the Gore-Tex PRO breathes significantly better than the thinner GoreTex Pac-Lite.
Great construction, fully taped seams, and quality zippers. Very happy with this one. I thinks this is a very well designed jacket. Get it on sale while it is available!

Matt W. makes a very fair and balanced review of the bag, I agree with almost all of his points: the absence of the second stuff bag and the coarse liner. I also wish the cotton liner was smoother, it does feel a bit "rough" and binds a bit against your clothing when you sleep. Not a show stopper, just a little pet peeve of mine. I also own a down Summit Park (BA) and the liner on the Summit is very nice. On the positives, this concept of the air mattress is simply awesome. I have a Luxury Camp Thermarest pad and this BA/pad combo can't be beat. I am not very tall or big (5"10, 169 lb) but the extra space of these Park Series bags makes a huge difference in my comfort level, I put a premium on having space inside my bag over weight and size. I originally ordered this bag and returned it by mistake, then re-ordered it again! Also having these two BA bags allows me the option to use the Buffalo Park as an overbag over the Summit Park for extreme cold. Great price for a great product!

I just got mine a few weeks ago, and it has been a great surprise. I originally ordered one in cobalt blue, but was dissapointed on the color, so I exchanged it by a black one. This jacket is warm, and I think a perfect compromise of many desirable attributes. It offers very decent wind protection, water repellency (it will keep you dry unless it is a friggin' downpour) and it breathes well. Other reviewers have done a good job at stating that it can be used with a base layer in 30ºF weather, or underneath a shell for nastier conditions. I love to pull the hood up when it gets cold. This bad boy will not pill, and the exterior will allow you to layer with comfort without binding. Even though it is fleece, the exterior reminds me of a soft shell. It is cut a bit long and will allow some room for some layering. I'm 5"10 and 170 lb and the medium fits me comfortably. It is a tiny bit loose, but still fitting in the Arcteryx style. Expensive but worth it. It has become my favorite fleece jacket.

I wanted a very warm and versatile parka for ocassions such as winter camps, a stroll in a cold day, or for watching a game in the winter, where wind and waterproofing is of great importance, and for times when I need to be out on a cold day when I will not be doing strenuous activity. I just came back from a winter camp with my kids and the McMurdo passed my expectations with flying colors! The black one I got is easy to blend with other colors, and versatile. Definetely a warm coat and I think a very good value. Runs a little big so make sure you try it on before you buy, or order a size smaller than what you normally wear.