What is it that they do that factory barrels won't? If I do my part with all factory barrels I have shootl sub moa, and with a couple of my carbine barrels they will nearly always shoot one ragged hole with ammo they like.
#1 biggest to that comment, it just what you said, ammo they like. For the most part I can make ammo that a specific T/C made barrel will like, it is rare that you find one that cannot shoot at all. What makes the non-T/C barrels better is that they will for the most part not find a load they like, but you have to work to find a load they don't like. Much Much better chamber dimensions by SAAMI/ANSI/CIP spec (we'll stay away from wildcats for a minute), a damn chamber that is actually centered on the bore and not on the barrel, a real throat cut, not a throat highway, a real crown and not one that drifts 2-3 degrees off the x axis (thinking of the y as the bore) YES I saud 2-3 degrees, enough to see with the naked eye. A match bore and not a hill infested bore, etc...etc...
Now, do T/C barrels suck? Not all that bad, many are fine shooters, but if it means spending only 50.00 more you might as well spend the 50.00 and end up with a 100%-er rather than an 85%-er. I have also seen bad barrels come out of all the major players, no one is perfect, and I have seen T/C barrels that will just plain shoot until no end.
When you look at the overall picture, that is the way I see it.