I got this shirt today and the material and weight feel great.  The compression is nice as well.  It felt great and fit well everywhere (almost).. only issue is that the sleeves were too short.  I saw some reviews here saying they ordered 2 sizes smaller.  So I ordered a medium (my regular size)I thought that if anything it may be too big on me (based on reviews here).  Nope, not the case at all.  I'm returning it for a large.  Btw for reference I am 6'1, 165. Not sure of my arm length, but they are not abnormally long or anything. Not deducting any stars, as that's they way it goes when you buy clothes online ;)

Update- Ok I received the large and it's definitely too loose, so I would say stick with the medium if you're my size.  Yes the sleeves are still also a bit too short with the large as well.  Not sure if that is on purpose (this was my first compression shirt) or if that is specific to this brand.