I use both emulation and real.
Emulation is a lot more FLEXIBLE using just the "one" machine, in so many ways as described by others above. And I can take it on the road with me.
However, the real thing is a lot SMOOTHER in both graphics and sound quality (i.e. 50 fps means exactly 50 fps, not 49.5 or 50.5 due to windoze process priorities). Plus when you need something that needs the speed of a 68060, you need the real thing (for now...). So I prefer games on the real thing (with VGA monitor of course). Also emulation though very close is not (yet) perfect.
Keeping it objective.