TSons are an elite army. And seeing their thing, they will trounce anything with a 3+. 2+ might give them trouble, but with all that psy shit going for them too.. cursed earth and whatthehell, they will be tough to dislodge. Especially terminators, rerolling 1s, buffed with Precise Timing and Ap3 Weaponry.
Expensive, yes. Very much hurting, YES.