Well, bottom line must be that the G-Rex isn't a good choice if the goal is to run OS4. If OS4 is the goal, either go BVision, Mediator or Zorro busboard.
For OS3.9 or lower the G-Rex is a nice expansion, and will surely boost the performance of the computer, enabling the world of cheap PCI cards. The problem would be the rev. of the Blizzard PPC board.
Is it possible for someone to make a programme that can surely determine which rev. the BPPC board is, so both rev 1.1 and 1.2 is included? Maybe a suggestion for Pirus WhichAmiga tool...
I'm just glad my BPPC 060/200/SCSI is rev. 2; I'm hoping my new board will be rev. 2 as well...