Axe FX

I have one and love it, what are you wanting to know?

AxeFX is a class of product called an “amp modeler.” It, along with the Kemper Profiler and the Line6 Helix (and the older POD HD series) work best when they fully REPLACE a traditional amplifier and separate effects or foot pedals.
I have the AxeFX with the foot controller. What that means is that set up foot pedals to do this:
1: The clean channel of a Bogner Shiva, with a laid-back noise gate, some effects, and a 2×12 cabinet loaded with Celestion cream speakers and mic’d with a Royer R121 ribbon mic at a 45 degree angle.
2: Some compression leading into a Vox AC-20 and mostly the rest the same (consistency, plus, it’s what I like) for a slightly break-up tone
3: A nice Wah pedal (that turns on when I move the expression pedal from full bottom position and turns off again at full bottom automatically), into a Splawn Nitro amp with a solid crunch, a tighter gate, some reverb, and again out to the same cabinet, speakers and mic (you can customize these for each and every setting – I could run one preset into a Pignose speaker if I wanted to)
4: Heavy tone with an EVH5150 Mk3 after the wah, a MUCH tighter noise gate, etc…
You get the idea. Basically, it simulates a hundred or so different amplifiers – REALLY well – as well as a multitude of effects, speaker cabinets and microphones, even with different mic positions.
I run this right into my computer and home studio so I can record perfect tones easily and quietly. I also run it to the power amp section of a tube amp (which I will soon be replacing with just an ordinary powered monitor so it doesn’t color the sound) for rehearsal and gigs. When I play gigs, they just run the out from the Fractal right into the board and push my exact tone through the PA system – no worries about shitty mics, or the guy that just hangs a crappy SM58 in front of the cone and calls it “good enough.” I can get my exact tone, night after night, gig after gig, venue after venue.
Syn currently uses only the effects loop portion of the AxeFX alongside his Hellwins, but he’s expressed an interest in moving full Fractal in the near future.

It’s a serious investment. I think a brand new AxeFX with foot controller and expression pedal is a little over $3,000.00 US. It is also VERY feature-rich and can be daunting if you don’t approach it methodically.

Not sure what Boss pedal you have, but it’s unlikely a correct comparison. The ONLY things that exist as a real comparison are some Line6 products (the old Pod HDs or better, the new Helix) and the Kemper Profiler. The AxeFX is a serious, professional piece of road-worthy gear – it’s in the touring racks of most major guitar players, including the Vais, Petruccis, etc. Metallica now get their entire tone from them – no amps, and Periphery has pretty much done the same since their first album. Trivium use the Kempers exclusively, but the idea and the tech is essentially the same.

It’s definitely a game changer. Other than the Kemper – I haven’t heard anything even close, (and I prefer the AxeFX). I have used it extensively in the studio and I defy anyone to tell it’s not a real amp being mic’d. Amp sim pedals ALWAYS have a certain amount of fizz when you get them too saturated. The AxeFX does not. It’s an incredible piece of gear!

Feedback is microphonic. As long as you have a monitor of the signal on stage with you, you can generate feedback loops just fine, and it will still “show up” in the signal that goes to the board.
In fact, there are two things that can permanently shut down feedback:
1. No speaker – the speaker is a REQUIRED part of a feedback loop, so if there’s no speaker pumping out the guitar signal, it can’t be “heard” by the pickups again to generate/close the loop.
2. Pitch shifter – if you change the pitch during the signal path, like with a drop pedal or whammy pedal or similar, there’s no static notes to generate the feedback loop, either