for recording purposes, I've always thought the modeling stuff was fine, especially when you can direct in. Anything Axe-fx will be of much higher quality than anything Johnson or Line6.
in the gigs, all of the modeling amps I've played while on a clean setting just haven't been able to cut through drums and bass like a tube amp can. Distortion was ok. The biggest workaround was to direct in to the PA system, but that's not always an option, and IMO it's kind of lame.