After a few months of playing my Profiler through FOH speakers (main outs) and/or a powered monitor (monitor out), I decided to use the internal power amp to drive an unpowered guitar cab. I turned off the cabinet simulation, and connected my home-built 2 X 12. The cabinet is a clone of an Avatar open-back design, and the speakers are Webers: one Alnico Blue Dog (a clone of a Celestion Blue) and one Alnico Silver Bell (a clone of a Celestion Silver Bell).
Holy crap, it sounds righteous. Every profile comes to life in a way I could not have imagined. The profiles all sound much more dynamic - probably due to the high sensitivity of the speakers. Now, if I can EQ / otherwise massage my guitar channel in the PA to get close to that cab, I will be a very happy camper.