I've literally just finished completing the rolling chassis, built using my tc02c + the conversion kit.
My spur gear cover too has a small chunk of plastic missing from where the spur cover must have been attached during moulding, I'd rather it wasn't like that but I'll soon forget about it as it is quite minor.
I also had to remove some flash from the upper rear section of the g/box casing (where the 2 screws secure the shock tower,though again it was a minor thing & the rest of the g/box assembly was ok. I noticed the layshaft bearing (in the L/H half of the g/box) doesn't fit flush on mine either but nothing is binding, though I may double check this as there is a little friction but not sure yet if mine just needs running in.
Can't comment on the gear diff as I've built it using the B5M ball diff but on this thread:
http://forum.teamcracing.net/forum.p...extra=page%3D1 said the diff was notchy once assembled so used a 2nd gasket which he says worked.
The only thing I would have liked to see is better access to the lower motor mounting screw but that's not really a build issue...