Ordered a M and I love it! Runs true to size! Long enough for arms, finally! (a problem I usually have is the sleeves not being long enough), though sewing pattern doesn't line up the stripes. Fabric is comfortable, but I can see potential for the white band to stretch out over time. Takes a long time to ship (approx 3 weeks), but well worth it, I will order again! 5'4, 130lbs, usually wear a size M.