The XXX is still one of the best platforms out there...and as long as you can get parts, it will remain competitive for a long time!
The XXX does benefit greatly from the TLR upgrade kit, but the true "secret" is to install and maintain your ball diff and keep your bearings cleaned and lubed. Good tires, a free drive train and a little bit of experimenting with weight placement will put this truck on the podium every time.
Zach has been driving the hell out of that ol' Pro-2 truck and doing a great job of keeping it straight!