Among my gaming group, one player says TK are OVER powered and the others just have a deep respect for my army. I had one draw, where I stupidly exposed my heirophant and he died turn 2 (yes, I still pulled a draw!) and the rest fairly solid victories with my TK's. They definitely are better in 2k and 3k games, which I play, than smaller games. Though I won at 1k too, the army just needs to be played differently.
I'm suprised FEAR hasn't come up yet. That is one of our biggest strengths IMO, never forget those fear checks. And its just a matter of relentless magic, reliable when you need it, and good manouvring.