
I started with an HB LSP which I spent a small fortune on making durable enough to race, upgraded hinge pin holders, better shocks, 17mm conversion etc. and it was pretty competitive but just so heavy.
I changed to a CEN Matrix TR Arena and jsut found that a complete PIA and only kept it a couple of months before changing to a Losi 8T. I've found the Losi very durable, still on the original A arms and about the only thing that let's it down are the rear outer hinge pins. I've now changed these for the Mugen MBX5T outer pins as they are supposed to be stronger.
I also bought a new 8T RR and then converted it to brushless using the Tekno conversion with a Neu 1515-1Y motor and MGM 16025 esc and it drives very well. Nicer to driver than the nitro although you miss the noise and smell. My nitro 8T may not be getting much use in future as the B/L is just so much smoother to drive.
I've never had an Xray but the quality looks very good, I went with the Losi as even here in the U.K. parts are easy to get and reasonably priced when you do need them.
I think most of the better quality manufacturers all make a good product and it will boil down to what you like. Try and see if people at your local track will let you try there truggy's so you can make a comparison. Different people drive in different way's and what suits one person may not suit another.