Recently reports on many forums (including here) are that the PzIII and likely others are now having there trackpins glued at the factory rather than relying on the interference fit -- good for endurance, harder when you wanna take the buggers off (but its not impossible).

Go with the PzIII S&S, you wouldnt wanna shell out for a Tamiya then find you don't wanna be in it - plus with them (Tamiya) theres building, paints, glue etc, factory errors/fit problems/part troubles and even if you've shell out a few hundred for the kit, and build it, you still aren't RTR and need all the crystals and receiver gear, controller blah blah). Heng Long - cheap, tons of upgrades available and RTR out of the box (unless you're really unlucky)