Great shirt if you do not need to use the buttons. The problem is not the size of the buttonhole but that the buttons are flexible, made of rubber?, so they bend when you are trying to button or unbutton the shirt. The fabric is thin which is very good for warm weather but also means it is fairly transparent (in case that matters to you).
I was recent had skin cancer and decided to purchase a tropicwear shirt. I found the shirt comfortable in our early spring day of 80 deg. I'm glad I checked the size chart and ordered a size larger than usual, I didn't want a snug for for kyaking and other outdoor activities. It washed very well. I found the buttons a rubbery like texture which prevented the fabric sliding through. This was only on the womens, my husband has 2 tropicware shirts with plain plastic buttons. Colors are limited.
This line of sport wear is excellent in texture, fit, wearability. I still have a shirt from over 10 years ago that is still useable, but looking finally a bit tattered.
I still have a similar shirt in size M that is about 5 years old. The new shirt fabric is thinner and softer, but I had to reorder a size S to get the same shoulder width. The waist & chest are still a little larger than the old M and the cut is straighter. The old version flared out at the hem. By the way, the dusty green is much cooler & paler than the dark celedon.