It's at the very end of the rotation and won't run unless it gets mapvoted (like it did today), for the most part so you don't need to worry too much. I can see why it sucks as a tanker. Let's see how it is with the reduced jeep collision damage (tanks won't die to turbojeeps) and make further adjustments if necessary from there. The bridges perhaps should spawn less jeeps compared to the mains.
We have turbo jeeps on 3 maps: El Al CTF, Market CTF, and Guadal CQ. On El Al CTF it has been there for ages. Market CTF is a brand new map and actively being adjusted. Initially we had no turbo on, that but the majority opinion was that it was needed. Ditto Guadal - very slight turbo, and code has been adjusted to keep them from killing tanks.