The Costco ones are wide in the shoulder/arms and a good length, but made with heavyweight cotton and sturdy. I switch between that for colder weather and Sifr Beanstalks for the summer, which are thin, with shorter sleeves, nice taper but narrower shoulders and longer than usual. Both are well-made, I've about 10+ combined, washed 30-40 times and none have changed shape. I like them better than Uniqlo and AA 50/50s.
Edited by accordion - 8/29/16 at 8:20pm