Oh yeah there is. Softsynths are fine in the studio where a crashed computer just means a reboot. But in a live venue downtime caused by crashes is totally unacceptable. Dedicated hardware synths are much more reliable and have well designed user interfaces that make using then in a live situation much easier.

Hey that is not to say that one day I wouldn't add a laptop to my keyboard rig for playing live gigs. But rely on a laptop alone ???? NO WAY. I work daily with computers and know too well that their performance and reliablility is totally dependant on the the applications they run.