For the first few weeks on him I used RoP near the center of the room and just barely moved. With iLvl 487 gear it was about 90-95K for me.
Not bad, and it was enough as a caster for us to easily down him, but I improved a lot by switching to Incanter's Ward and moving with the leg circles. My dps with the same gear and talents (except IW) went up about 8-12K, consistently. But, maybe more importantly, it was
A LOT more fun. Just scorch and blink your way to the next leg circle, hitting an occasional Arcane Explosion to keep the stacks up.
I've been doing this with a haste build, since your mana regen is definitely lower. There is a bit more scorch weaving than with RoP, but not near as much as I had expected. Most of the time I had been casting IW only before a crush, but obviously you could have the buff up 100% of the time on this fight (with the trade-off of a few more scorches).
Even if the damage wasn't much better, its extremely liberating not to use RoP or Invocation whenever possible. I really look forward to this fight now. God, those are just awful capstone talents, from a 'fun' point of view.