GT7 is too smooth for stock racing.... expecially stock TC racing - for offroad it would be fine...
As for the argument for the LRP's... I have 7.1's in both of my XXX-s's, but I mainly run mod.... the SR is a fine ESC, but will not be quite as smooth for Mod racing. they are built off of the same platform, just different software profiles in the two. The quantum comp is well worth the money if you can find the extra dollars - that is what I run in my buggy and it is great!
Wilde