I love the feel and fit of these shirts when brand new, but after a few washings, they do shrink and seem to also fit looser. Also they are cut a bit short. I'm 5'3", and with no shrinkage they fit fine, but after one to two washings (cold water wash, low temperature dry), they shrink at least 1" in length. Certainly if you're taller than I am, I don't think you'll be happy with this shirt. Note: We bought a second laundry hamper just for the "cold wash - low dry" clothes, so I KNOW these shirts have been washed and dried according to directions on the label; and they still shrink.
I have a couple of these shirts in my closet from years past and the quality and fit was so outstanding that I thought I'd order more. Although the supima cotton feels wonderful, the fit is vastly different from a few years ago. I ordered a regular M. I am a slim size 8 (with thin arms) and the sleeves are so tight that it was uncomfortable to move and bend my arms. The sleeves were bunched up above my elbow. Who is stitching these? Is there no quality control? The shoulder seams are also a bit pointy where the shoulders meet the arms. This is not the quality I was expecting or hoping for. I am sadly returning these and will be shopping elsewhere.
I'm a pretty standard size 12 and typically I've ordered a size Medium. I really like this shirt and I intend to order more in different colors. However, if you are looking for a shirt that is a little more generous in its cut, this is not the shirt for you. The sleeves in particular are fitted. I also wish it was just a smidge longer.