What exactly is great about the amiga custom chips? Slow and Low resolutions, poor sound quality, slow floppy...i think why the chips were good was because the architecture as a whole meant the chips could function independantly of the cpu, as happens with modern PC GPU's. I have an A4000 with a CV64 and a Prelude and a zorro serial and parallel port and a Zorro IDE interface and a cyberstorm 060: i use none of the original custom chips including the 3.1 ROM and i would never go back to a vanilla A1200 except to play games.
The advantage of custom chips is more uniformity in the code that needs to be written to make the computer do something and hence more stability. the disadvantage is obsalence and even slower hardware progress,
