The PowerPC cards don't seem to give much of a pay off. When they were released they were competing against the first Pentiums. Nowadays you are competing against a PowerPC G4 or WinUAE.
Some people have overclocked the 060 to 80MHz and one got to 100MHz with the FPU not working. That makes a very fast old Amiga.
There is still talk of making an FPGA accelerator card which would give you an 060 @ 200 or 300Mhz.
If you don't have the money and need power use AROS or WinUAE etc.
