I've had this jacket (cardinal red in Med) for over 2yrs now and it's definitely my go-to hard shell jacket! the event is fantastic and can't be more pleased w/this jacket. whether hiking, climbing, skiing this will keep you dry and comfy all day! the side vents are most useful when it gets a little toasty and the hood is a perfect fit for any helmet!
The sizing is a good - like i mentioned, i've got the med. and it's a perfect fit for me. not too snug & a decent amount of room for layering (i'm 5'7 & ~150 lbs). i would like the cut to be a tad bit shorter for me but it still fits very well!! big fan of rab products!! arc'teryx are nice but just way to $$$ ...these days there are way too many options for good, quality gear.. i'll usually look for rab/mammut products first.