I am heavy into mini-zs and was heavy into xmods and still have heavily upgraded xmods

The short: Xmods are for fun and outdoors, mini-zs are for the track

i made an xmod that is competitive against mediocre drivers but it is too heavy to ever be competitive with a mini-z. it also lacks tuning and there were issues i was never able to overcome...i could write a lot, but souping an xmod up to race is not worth it but they are fun for just bashing around and speed runs outside.