I use that as well as the hardware Torpedo unit. Indeed, it took me awhile until I was able to get decent sounds out of it, but it can be done. I've used many speaker simulators - software and hardware - and this one is my favorite.
Here's what I suggest - start with only one cabinet. Point an SM57 at it as close and head on as possible. Then run through each cabinet and listen. It's not a bad idea to start with the kind of cabinet you think would be appropriate. Keep the 'amps' off, and turn off all the other fx - just a plain 57 pointed right up to the speaker.
Most important thing is to listen to the guitar in context with the music. Also - play for a few minutes on each cabinet. See if any of these help.
Richard.
