I have had a sub kilo for about 5 years, and have spent maybe 40 nights in it. I am 6'4 and 195 so tall and thin, my long bag is definitely snug around the shoulders. It is very light for the price and I think they achieve that by making a very slim bag.
I don't have any other complaints on the bag, it is pretty warm down to its rating, and has held up well, especially considering my 85lb black lab often shares a tent with me and loves to stomp all over my bag in the morning!