Emulators depend on the PC hardware. Although, most PCs today can emulate and play games with accuracy, it is not the same thing. A typical example is to play a game in emulated Amiga and then play the same game on a real Amiga. You will notice the difference in controls. Visually, it can be the same, but controls suck big time in emulation.
Personally, I am not using winUAE for games. I only do stuff that I can't do with 18MB of Ram...