I've had my Hyper 10SC for about a month now and thought I would share some observations.I tried the VXL 3500kv combo but it did not "feel" right.I switched to a Novak HV PRO 6-5t(3700kv)combo with a 14t pinion gear and use a 5000mah 40c 3s Lipo.It gives great performance,plenty of torque and LOW temps and the motor has a 5mm diameter shaft that handles the motor torque.
Robinson Racing make a 3mm to 5mm shaft adaptor so you have a bigger variety of pinion gears to choose from as 32 pitch pinions with a 3mm hole are pretty scarce if you want to use a 540 0r 550 size motor.
I have a Slash 4x4 as well but I have to say that the Hyper 10SC is by far the better handling truck and my choice for a racer.Just make sure you put in a decent steering servo-I use 14kg Hitech.
Regards-JETHRO