Drove the XB4 today and put 5 battery packs through it. New to 4wd buggy so it took a pounding - hit the agg pipe many times and did a bit of cartwheeling! It held up well - nothing broke and diffs still feel 'buttery smooth'. The track was also very rough as it's about to get a facelift, so there was a lot of rocks coming out of the clay and small holes on the surface and it ate it up nicely.
The car certainly turned well, but I can't comment on much else as I don't have any experience with anything else.
Happy customer so far.