In terms of what most Axe users are interested in, there are two principal ways of amplifying / outputting sound - 1. thru a traditional guitar cab (with whatever amp you might choose) or, 2. thru a full-range, flat-response monitor (either powered or passive).
It can work extremely well either way, but if you want max versatility, you would choose FRFR, and use the pretty wide variety of cab sims available, both stock, and from 3rd parties, which can also be loaded into the Axe.
Here's the thing that some struggle with though: if you choose FRFR, it helps to understand that the monitor is now a sound reproduction device, whereas a traditional cab, with it's very colored response curve, is really part of a sound production chain.
The more neutral the output monitor is, the easier it is to take advantage of the tone-shaping tools in the Axe, and the more consistent your results will be.
And that helps to achieve the best tones thru the FOH system, which the Axe does extremely well, and arguably better than most miced traditional amps.
I've got an Ultra. I run it with a Carvin DCM150 in stereo to 2 Port City OS 1x12 cabs. I love it to death. You have to try one to know how good it is.
I am an idiot. I was doing some work with a project that was already progress and the guitars that been previously recorded had been done with an earlier firmware version so for continuity's sake I flashed my Axe to that earlier firmware version as well. Just this morning it occurred to me that I had never upgraded my Axe back to firmware 9.0. Now everything sounds the way I had originally dialed in again.
Hey Cubucket, I was thinking of going with the same setup you have but with a 2x12 Port City and running the Carvin mono. I ended up with the Atomic instead but was thinking of adding the standard guitar cab setup as well. Do you miss being able to use the cab sims, or does the Port City's sound make up for it? What speakers do you have in the PC?
I have used the Axe-Fx for over a year and am still amazed at what it can do. However, switching from a traditional rig to the Axe requires a fair amount of learning, but I think it was well worth it.