I currently own from that range the Hyper 8.5 pro kit and the Jammin X1XCR Pro Team Kit (with up-grades to just under the X2X level). Engines are OS VZB V-specs, (blue head and black head) OS pipes, etc. Also have a Kyosho MP7.5 Kanai III, Kyosho Inferno US (for spares or re-build later - got it cheap as it's busted) and my original XTM XT2 RTR. During the builds, I found the Hyper and the Jammin to be very nice, high quality and no hic-cups. Driving wise, they can both be competitive and both do well especially on the European Circuits. (Driving / Set Up skills both count big time in this sport).

Having said all that. My current "race" bug is the Jammin. I personally feel that it's just a couple of notches better and drives better to my style of driving. Stock from the box it came with a fuel tank trigger, the Hong Nor purple 3 shoe clutch, fiberglass disc brakes, Hong Nore aluminium Big Bore threaded shocks, CNC aluminium Z-brace chasis stiffener, better diffs and an over-all lighter package. It also has much more upgradeable parts which I've added to mine like; lightned spur gear and outdrives, one piece engine mount (back order), aluminium posts, hardened & lightened pinion gear, CNC aluminiun rear wheel hubs, pivot ball steering knuckles, CNC aluminium center diff & brake mounts and a few other things I can't remember at the moment.

I have no regrets buying either one (or any of them for that matter) but IMHO, I find the Jammin X1XCR much more suited to my style of driving, more upgradeable and it was the best supported by my LHS at the time. That's another important factor, parts availability in your area.

I have yet to see the Jammin X2X in person, but I'm sure it's as top notch if not better as the Jammin X1X CR Pro Team Kit. I have seen the Hyper 9 in person and was impressed with it, however, I haven't seen it actually run on the track.

Good luck with your choice and no matter what....HAVE FUN.