I have been getting 7.5 minutes of run time with my NS12 TS1 at our club races.
Motor has great power also. Bottom end is good, but not like a more expensive mod motor and such.
I love the thing. For the price you can't beat it.
We run on a parking lot track with soda pop for traction compound.
Kyosho RRR WC with RD Logics Pipe.