Yamaha DTXpress/DTXplorer/DTXtreme

I have one last (yeah, sure!) question regarding user opinions on
playing with a monitor versus headphones only.  I realize this takes
me into the Noise Inducement Zone (the avoidance of which has prompted
me to look at electronic kits in the first place), but I'd just like
to find out what real, live e-drummers prefer.  I also understand this
is a wonderfully subjective matter, but I'd be very grateful for any
and all opinions.  How limiting is it (if at all) playing with
headphones only?

Thanks, again, for all of your excellent help.  

FX