To be honest, all I've done is tried this on once I received it. It's still way too hot in Kansas to warrant any kind of sleeves that go past the elbow. That said, here's what I think: I'm 6'0, 160lbs and bought the Medium. The color was true to the picture, the size was dialed in and it seems to be a very comfortable jacket. The sleeves are perfect, not too long but aren't short either. The feel is lightweight and will more than likely find its way into my pack this September when I'm in Colorado. I'll update this review once I put it through some fun.
After 5 days in Colorado I have some more input for this jacket. I wore it every day at some point and it became my go-to jacket. After walking around town, bagging a 14er and doing day hikes I'm impressed. Even though is was windy, and the fact this isn't a wind shirt, here's what I did. With just a t-shirt on underneath the evenings got a little cool for the jacket at 40-45 degrees. Going up Antero, and with sustained winds of 20 miles, I had to pop on my windshirt over it and a base layer to keep the chill out. On top of Tincup Pass (12,154') it was once again too windy for this jacket with a t-shirt underneath. Paired it with a buddy's OR Ferosi and the two kept me warm enough. I did where this jacket as the day would warm up and was able to keep it on, and stay comfortable, well after the noon mark.
All in all this is a great jacket for it's intended purposes. I highly recommend and will continue to stash this in any bag I take anywhere.