Excuse after excuse
XX4 is a PAIN to work on, always has been and isn't something you can really do anything about........
Apart from that overall i'd say it's probably the best all rounder, it just works with one setup and is pretty fast even now.
Looks like the Yokomo is getting there after a few tweeks to suit the UK tracks, but like any 4wd car a lot of things are changed in the first couple of years to get it right.
I was at the first national the XX4's were running at, i think every single one on track snapped the front shock tower (Track was Marston's) - They had to quickly change that design but that's just one of the simple things they changed.