velineon E-Maxx

I don't know about this. Your perception of what is fast is probably limited to what you have experienced. What I thought was fast two years ago, wouldn't even come close to what I'm running now.

Since no one has the Velineon yet, no one has been able to do any experimenting; but, according to specs, the Traxxas system can only do 3S. Most here are running 4S lipo (or its nimh equivalent) in their Maxxes.

I would be very hard pressed to believe that a Maxx running on 7 cells would be anything stellar. 7 cells is only a bit above 2S lipo. I'd consider that to be way underpowered. I have a truck that goes around 10lbs in bashing form and I run 5S lipo (equivalent to about 15 or 16 nimh cells) in it to get REAL performance. At least 12 cells is needed to comfortably do a consistant 30+ mph.

If you want to put something into your Maxx, get something that will do at least 4S lipo or 12 cells.