I bought a G-Rex for my A1200PPC because it was cheap. after an hour of trying to get it working (and failing), it got so hot I could smell burning, and the hot glue on the board melted. When I removed the board, my A1200 would no longer boot - it was dead and I had to order a new motherboard from Eyetech.
I sent the G-Rex back and got a mediator instead which worked flawlessly.
Bottom line is that G-Rex is faster but its a pain in the arse to get it working, there's no support, less drivers, and risks damaging your Amiga.
