I think so highly of the platform I bought 2 of them

First upgrade you should consider is a secondary gear cover,either from ebay for the aluminum one or Losi's $5 plastic one.Either way you need to close off the back and bottom of the gear cover to avoid rocks chewing up your gears.

Depending on how hard you intend on using it and what model# you have you should buy a spare set of cvd's and a-arms.I mentioned model # because they upgraded the axles and cvd's somwhere around kit #8000 as well as the clutch springs and a couple other niggling things and I have yet to break any of the upgraded ones