I have been playing software synths live for awhile with no problems. I do keep a hardware unit just in case.I use M-audio keyrig and some of the Native instuments stuff. Using the Evolution UC33e I can control just about anything I want to. I use an Averatec laptop with the Echo 24 bit sound card and monster cable to the direct box. M-audio key rig is a really great setup with four modules including the B-3 sounds,FM,Analog.
I really like the ability to by another whole instrument for 200.00. The sounds are pristine.