That's a pretty good touche. I found my vocal technique changed for the better when I started using the headset. On the other hand, I have seen some great singers whose voices I would die for bring their hand held mic back for those high notes.

I guess the headset isn't for everyone, but given all of the buttons, keys, and knobs that us arranger keyboardists have to deal with, it does offer the distinct advantage (or crutch) of always being by your mouth.