The combat shirt is a typical ACU cut sleeves sewed onto a Lycra moisture wicking shirt with a zip up collar. I got mine in temperate MARPAT, although they are available in several patterns.
I wear a medium shirt in everything. This fits me more like a large, with extra room in the chest, and some extra length in the sleeves. It is comfortable to wear.
When I receieved it, the color and pattern matched my Propper MARPAT BDUs almost perfectly. However after a washing (cold water, gentle soap) it has lost a shade and is now slightly lighter. It still matches and can be IDed as MARPAT though.
The stitching and build quality are good. Not quite as good as Propper, but they don't look like they'll be coming apart on me. The zipper looks sturdy.
There are two pockets, one on either shoulder. They have a velcro closure, and a small patch of velcro for patches. This outer velcro is too small for a flag.
In temperatures up to 90* F is very comfortable to wear. Its still early in the season, so no genuinely hot weather yet. Its liberating to not have the two layers of cloth between me and my plate carrier, and yet still have something protecting my arms. I would say buy one, because for $25 its a really nice piece of gucci, that looks cool and is functional. The only downside really is the fading of the colors.