I've had a play with Griffin's toy and liked it. It's better than Ultimate Bumblebee for sure. The transformation is a little fussy, certain bits have to be in place first for it all to work, but it was an enjoyable challenge getting from robot mode to vehicle mode.

I may wait and look at getting the Japanese MP version instead if I can get it at the same price/cheaper. I could live with out the gimmick arm too, and at one point I triggered the sound effects too easily... but the transformation underneath it all is pretty solid.