1/5 Baja 5b with BL motors in-wheel...

[RC-Monster Mike]

Interesting concept - my feeling is that it is a better idea for on-road/speed runs, where the motorized wheel may be less detrimental to overall handling(lots of unsprung weight). Unless there are some fancy electronics, the motors are either wired in parallel(behave like a locked diff) or in series(behaves like an open diff or diff with no oil), so handling is again compromised and has less tunability. I imagine the motor performance may suffer after some time in a harsh off-road environment as well.