Thanks for the answers.

As far as I can tell, the speed improvements above and beyond any other Amiga system (except perhaps WinUAE) are due to the improved blitter, memory type and DMA, plus the increased speed of the CPU, whether that is their 120MHz 060, or the not yet finished N68050 in the FPGA.

The N68050 is more for cost savings than a means to go faster than their 68060 CPU card.