well, most guys that do boxing aren't going to be exceptionally good, period, regardless of what background they come from. That said, there are quite a few Thais who came from MT and became titlists, or even P4P fighters. Pongsaklek, Khaosai Galaxy, Veeraphol, Chitalada, Kyowa, Borkhorsor, Sorjarturong, Kingpetch, Chionoi, Payakaroon and several others all probably had at least some MT background, and several of those are ATGs (at least in their divisions).
There is a pretty distinctive "Thai style" to boxing (bear in mind that obviously not everybody fights this way, notably Pong, Chitalada, and Kingpetch). Generally it involves sitting behind a jab and grinding your opponent out, mostly with inside work jabs and crosses. The biggest strength (IMO) in this style is the conditioning. Thais are almost universally well conditioned and very tough, they're there fighting you from start to finish. They generally have pretty solid body work (both inside and outside) as well and are generally at least competent ring cutters. The weakness however, is that the style tends to be centered around being the aggressor, defense usually isn't stressed as much (at least not versatile defense, mostly it's just high guard). Some would say the fighters tend to be a bit flat footed so they can get outboxed. Relative to, say, the Cuban style, it's fairly crude, but it usually gets the job done.
