Just got one of these from SAC in size M and I'm 6'3" tall and weight 170lbs. The fit is pretty perfect except probably length wise it could have been slightly longer.
The sleeves are long enough for my long arms which is nice and it is a bit stretchy which is perfect to ski/climb with.

i was looking for a nice mid-weight powerstretch top to wear alone on chilly days and as a layer on colder ones. i thought this was exactly what i wanted, but looks can be deceiving.

for one, the sizing is different than all other arc'teryx gear i've used; it runs a bit smaller. not a problem as i could have easily swapped sizes.

the deal breaker for me was the hem, or mainly how it blouses out. i'm all for a drop tail to give some more coverage in the rear, but the bottom-back seam juts out in a skirt-like fashion. it looked like i was wearing a dress from the back. needless to say i returned this top.

the warmest and most comfortable base-layer out their! the zipper dose not chafe and it stretches with every move! very warm by itself! the only thing its odors get trapped in it so wash it everytime you use it. buy it!

Always spend the money on Arc'teryx, because it's always worth it. I've worn this as a midlayer on bitter cold ski days and have been very impressed (and warm). I also like this as a casual sweater type shirt for nights out. Yes, I like to wear my gear to the bar. I'm looking forward to using it as a top layer for early season hiking.

I love this fleece. The stretch makes it fit very nice, and it is as warm as a wool sweater. The price is not too bad either. Keeps apperance and shape well after washing.
Guess I'm going to get this one in another color, if I'm not going for Peak Performance new heli mid layer. Got the PP black light, and loves that one just as much as the Rho AR.