IMO I hate conceal carry shirts. The shirts have to be very tight (compression fitting) for the gun to stay put and not flop around. That was uncomfortable for me. Secondly, the material has to be very strong to hold a mid to full-size handgun. This makes the shirt unbearably hot in the summer and I live in PA. I can't imagine what it would have been like in the South. Another thing I did not like is that the shirt is designed to be worn under some other clothing. This makes access to your weapon very difficult unless the outside shirt was very large and loose. I have found much better ways to conceal my hardware. To give an idea of my body type in wearing something like this: 6'1", 215lbs, athletic build.
The shirt I bought after doing some research and thinking I got the best shirt for the money was the Undertech Undercover, XL in a crew neck style. I tried carrying a Glock 23, a S&W snubby .38, and a Sig .380. It held all of firearms very well; I just didn't like wearing it.
Trying to find a way to carry a chunk of metal on your body comfortably is a process. Try different things, ask (like you did here) for people's opinions... however when all is said and done, your opinion is going to be the one that really matters though. Good luck with your search.
afterthought.... I also ask, at stores, if I can take holsters and other carrying devices out of the box and try them right there. Most stores have been more than accommodating. Sometimes it requires me to check my weapon, mostly they just require me to unload the weapon.