yes it's different. it's like hearing your miked up amp through monitors instead of the amp in the room...unless you run it through a poweramp and cab. you need to keep that in mind or you may be disappointed.
Hmm! Not sure what to think. Back in the day when we were doing bar gigs, we didn't use PA systems or run through boards. We used our amps cranked up. I do go to a friends gig every once in a while. They use a small board and powered monitors. On of the guys uses a mic'd amp and my friend uses an Eleven Rack straight to the board. It all sounds good to me. But, it's probably not the same as sitting in my music room with the amp in front of me. Actually, I've played at my friends house using his Eleven Rack and thought it sounded really good. Maybe just a little on the hifi side. By the way, is the Kemper as easy to get around on as the Eleven Rack? That thing was easy to use and dial in. The Layout was very amp like.