I'm frankly shocked you mention the rc18 in the same company as the xray. I've owned the old rc18t, the new t2, the non pro xray and the pro xray. The non pro xray is comparable to the rc18s (but still marginally better mainly because the steering doesn't flop around like a dying fish), but the m18t pro (pictured below) is in a whole other league. Perhaps you thought I was talking about the plastic xray. I wasn't.

Also, I think those market figures you quote are US only. But in any case, what car is the current US champion? The xray. Furthermore, if sales figures are anything to go buy, then that must mean the HPI hellfire is better than the MBX5t, it sold more units. lol.