Nice quality, very soft feel and I would says fits slightly larger than, say, a fashion polo. I don't mind this so much as for golf the freedom of movement, rather than the look, is arguably more important. I'm 6' and 40" chest, so I went with the large and it does feel roomy. I'd be tempted to go down a size if I wanted a casual polo, but for golf I think it will be fine.
Also may be worth pointing out that the shirt I was expecting was described as having a 'contrast placket', ie. the shirt was white with a black contrast. This is not the case - the shirt I received was completely white with no contrast. This may have been down to me ordering through the App rather than the website, but Amazon have been informed. I decided to keep the item in any case as not worth the trouble of returning.