Well I originally bought my Axe-FX as an FX unit. The converters are TOP notch, and the effects are crystal clear. Blew everything I have tried away. Eventide, TC, etc. I was going to use it in a Egnater M4 + Triaxis/2:90 Rack. This was awhile, ago and I had a HUGE arsenal of tube amps and rack gear. Refrigerator sized racks and amps everywhere. Anyways, so I managed to score one (this was when there was a 6month+ waiting period). And as I had read and hear, the effects were STELLAR. Absolutely amazing. Like... I can nail Lexicon reverbs and delays with this thing. There are so many parameters that allow me to adjust, etc. I've actually ran vocals and drums, etc through it, because of some of the lush, filling verbs and delays I've gotten out of it.
Anyways, so naturally, I buy it, and I'm going to try out the amp sims. You know. Just cuz. So my first thing I did was an A/B test with the triaxis using the AxeFX going into the Mesa 2:90 into a Mesa 412 stack. After some tweaking, I could get my *Exact* triaxis tones. Same dynamic, and fullness. Everything. It reacts to my volume and tone knobs like a champion. I felt ripped off. I sold my Triaxis within the month. Since then, I started using it as a preamp, and FX unit.. eventually started selling more and more tube amps. Then I started using it for direct recording, but could never get truly perfect tones like I was as a preamp. Then I discovered user cabs. You can upload you own cab impulse responses, and when I figure out this, I replaced the decent, but not amazing impulses that came stock in the Axe, with different ones in all of my patches. Tweaked to taste, etc and now I'm literally getting every sound I could ever want.
But wait, theres more.
The customer support. The best. Ever. Firmware updates, CONSTANTLY. We are talking fixes and patches and new features on a monthly basis, almost always, and often times, closer to a weekly, and sometimes, even daily basis. Not to mention a feature section of the forum, where you literally ask for a feature, people vote on it, and if a lot of people want it, it often gets added. You can also request amp sims for Cliff (creator) to add in. They are also working a native Mac/PC editor (its in public beta) so you can adjust all the AxeFX parameters via midi on your computer. Its great, because I have sold almost all my tube amps now, and I use my Axe-FX for almost all guitar tracking, because I am confidant I can get almost ANY tone I could ever want with the AFX, and now I can have Pro Tools / DAW running, and adjust my parameters, etc. Its great for reamping too, and much better, native reamping support is supposed to come soon in a future firmware update. The editor is probably the Axe-FX's weakest point honestly. Then again, it is in beta and they started working on it very recently, but personally I just don't like the UI.
I dunno. I am not affiliated with fractal in any way, but if there is one piece of gear that has proven to be INVALUABLE, its the Axe-FX. I will likely never sell it, until the next hardware generation of the Axe-FX, which has been said won't happen for years and years.
I love my Axe-FX. Check out fractalaudio.com/forum Lots of great info and tips etc. Its worth the 2 grand it costs. Honestly, its worth far far far more than that. Its a $10,000 unit that you get for only $2k
EDIT: I too love all things guitar. Unfortunately the Axe-FX is really killing that for me. I used to have so much fun with 1390572 different tube amps and FX units and pedals and gear and giant racks, etc etc. Now Its all consolidated into a 2U rack space. Cliff posts on Huge Racks Inc, Rig Talk, Harmony Central, etc. Check out those sites for a lot more info and praise on the AFX as well. Sadly enough, its not as well known as it should be.