man, theres thread and lots of info on both bike already in this forum, click home up the top and theres a search button !, lol. there both great bikes im saving at the moment to buy x4r, its really what your gunna use it for if your a die hard pit bike fan thats gunna race and flog the guts out of it and benefit from the lxr linkage you would be better of with the lxr..... they both have same motor soo yehh,
and i hope if you buy either one you buy it from DHZ Mini Moto - Home as he is a sight sponser
good luck