I am 5'6" and wear a medium. i ordered an 8 and a 10 and am keeping the 10, which is a little large but, importantly, is a full 2 inches longer than the 8. this is important to me because several of my casual pants begin a couple of inches below the waist and, as noted by another reviewer, and as is evident on the model, the top hits just below the waist. also, it is cotton/linen and may shrink (since it is ivory, i assume it will see a few washings). i don't want to worry about the "gap", but i