ORIGINAL: Druss
for the cost i prefer the belt cp, it's $200 shipped and it's rtf (still needs some set up like all rtf but comes fully assembled). the biggest difference is the mx400 pro has an aluminum frame, belt cp is plastic.
The sad but funny part of it is if you stuff it, your choice is a bent boom on the MX or a broken one on the Belt. Either way, you'll need to replace it. The Belt CP is a more logical choice.