YES, they are funner than nitro
I spent 6 hrs at the track yesterday running thru packs; can you imagine how much fuel that would have been?
My set-up is basically Chad's. the reason my spings collars are so low is cause I tried cutting the springs. In theory they are suppose to be stiffer if you cut them, I think they actually ended up softer (don't recommend it).
Jimmy and I are running Fantom 7.5 turn motors. WWAAAYYY smoother than 550's, IMO. Another plus is that they are lighter. Jimmy sells the Fantom stuff, no issues at all and they are fast.