As a guitarist on stage I like having amps and a half stack. My collection is 6505, JCM900, Carvin MTS3200, Jet City, Egnater. I guess playing in small venues most of my life and having little practice spaces I like being closer to the cab, on large stages it can get weird when monitoring is not done properly and I think on large stages is where you really need a good monitor guy. Outdoor stages, where you aren't really getting any reflections from the room and the bass can get out of control on the stage make this even more important. Either way I still cant see myself ever wanting to use just a preamp and just monitoring thru the floor wedge.
As a sound guy, either at FOH or in monitor world. I want the artist to be comfortable, and I actually prefer to mic cabinets even with a DI out or preamp out (even on bass). It just seems like an easier mix situation, even though its not quite like an Amp sim there is something about the dynamics that does not feel right for me. The next best thing other than micing a guitar cab is using the H&K Redbox, which requires speaker output from the amp and still needs speakers to work properly. I use this sometimes as a backup on larger events in case the mic gets knocked over or the mic/line goes out. this still has the dynamics seems just to have a bit more attack, which can be good or bad, sometimes I pan them opposite and run both.