TTi International stands for (or used to be know) as Trappers Triangle. A few years ago he used to do the Dominion shows selling AR's built on DPMS lowers. They looked pretty decent, but I don't know anyone on that shoots a TTi built gun. When I asked a former VA State Rifle Team captain about TTi, he said he'd never heard of them. I assume you're looking for something beyond a basic AR either a race gun, space gun or mouse gun. I don't think if I was looking for a Service Rifle, they'd be my first choice but they may indeed be decent, for a race or space gun they may well be the go to guys. In the past I know TTi supported a couple of local IPSC shooters who sang their praises across the State, but so would I for free gunsmithing. As far as I can tell, that's their claim to fame, but bear in mind I don't know squat about the IPSC scene.
That said, I had Trappers rebarrel and do some trigger work on a M1 I had, and they did a good job at a fair price.
If you're in VA and want a service match AR, why not contact one of the guys that builds rifles for the State Rifle team? I believe at least one of them advertises in the Bullet, and if you know any active high power shooters in the state, they should be able to give you some names.