I've just returned from racing mine at our National Championships, I have some findings..
1/ The car is horribly under geared, at England Park ,60-65 meter back straight, using a 29t second gear (and that is the bigest you can get!) it would still be wound out about 2/3 of the way (I used a Novarossi NS3);..that was with 60mm foam tyres!
2/ The car handles better on smaller tyres, i.e. below 60 mm, just feels more planted, canges direction quicker etc.
3/The stock Crownwheels and Pinions are pretty soft (the gears inside the gear boxes), I used Tamiya moly grease on them, they lasted a total of 2-3 hours, although they didn't strip, they were showing sufficient wear to make me decide to change them.And yes, they were shimmed perfectly!
No Doubt Kyosho will release some hardened gears.
4/Handling wise I'll stick to what I've said earlier, turns in better and gets in and out of corners faster than anything out there.....I did miss the one way front diff on that track though.
5/ I think if you run on car-park tracks , this is the car to get.