Having finally gotten a chance to play around a bit with OS4.1 Classic on WinUAE, on my system it's pretty poky, but then I've got a pretty old and creaky system (Phenom X4/940 @ 3ghz, 8gb DDR2 RAM).
Doing a new build in a couple of weeks (FX-6300, 16gb DDR3 @3200), we'll see how it behaves then.