I benched a lzx operation on a 1,1GHz Pentium III once. WinUAE was 5 times faster than my 68060/50MHz.
PC ram is faster, JIT flies, PC disks are faster, PC video is faster...
As for games, the slow chipmem has no impact in WinUAE. 68060 boards have very slow chipmem (my Phase5 has).