I raced my Gator at the weekend (just sold the b4 and waiting far a cougar) with a 19t motor and different tyres. True the shocks are rubbish but I had so much fun racing it I'm tempted to take it again.
Long term I think it might shake itself to bits before anything actually broke as its all self tapping screws holding it together.
True I was mixing it with perhaps a lower heat than normal but it was up against B4's and it kind of held its own.
Only thing is it seems to be alot dearer now than it used to be. It wasn't that long ago that a kit without speed controller (standard one is for 540s only anyway) was going for about £60-£70. Not now though.