I have had this coat for over a year and wear it about 9 mo out of the year. Living in Chicago I have found that this in combination with a hoody or fleece + base-layer are all that are needed for all but the coldest of days. When climbing or backpacking it holds up surprisingly well, but I have also been extremely cautious because the material seems like it might rip easily. So far so good, though.
I'm about 5'11, 155 lbs and a medium fits perfectly with a bit of room for additional layering underneath. The pockets are also quite toasty and warm. Probably worth it to pick up a stuff sack to go along with the coat. I use the medium sized stuff sack here (tight squeeze but works): http://www.outdoorresearch.com/site/ultralt_ditty_sacks_set_of_3.html