But by the time you get up to SIMMs/DIMMs it all has to go through the onboard memory controller, doesn't it? That's the reason I haven't put faster RAM in my 386, even though 12MHz RAM on a 40MHz system is an obvious bottleneck: the memory controller can't keep up with anything faster.
Really, that's the problem with the whole idea: there's a lot of hardware in the Amiga that's designed to be superceded by things like RTG, but not replaced with a functionally-equivalent enhancement. In order to replace all of it, you'd likely have to replace so much of the system board that it'd be easier just to build a full system replacement...
