if you dont feel like switching the center diff to the hb and getting the plastic spur then just get a hardened steel pinion for the ofna steel spure...
Yes, go for the hyper 7. I have both. I like the Hyper 7 a lot more. It handles so much better. The MBX is a little too narrow to fit battery packs on each side. So you would be stuck with your batteries all on one side or just 1 pack on the one side. I run one 4s pack and I have had trouble in the past with over heating my Lipos. The newer generation Lipos I'm hoping will be better at not overheating.