Hi, thats not an easy decision! It mostly depends on your needs and the way you like to work.
The advantages of the Axe II
- USB Audio
- nearly endless high quality effects and very advanced routing posibilitys
- Dual Amping with quad cabs (two in stereo)
- PC/Mac Editor
- available footswitch (Kemper will have one too)
- tonematching lets you match your sound to an isloated guitar track of your favourite artist
- rackmountable
The advantages of the Kemper
- profiling actuall amps sounds better than tonematching (IMO)
- easy and userfriendly interface
- steady growing library of high quality profiles
- lower price (1000€ difference in germany)
Of course you will always find someone who will argue over these points, but I think this sums it up quite ok. Depending on how important some of these points are to you, I would make my decision.
If you choose the Kemper you will need some kind of interface to your mac, since it won't support USB audio, since its hardware is not made for that. The interface could be USB or Firewire. Presonus makes really good interfaces and if you choose the Kemper, you will have some money left for that.
I guess there will be a PC/Mac editor of some kind, there are many threads in this forum about it.
The Axe is probably the better "All-in-one" unit. Since you can do anything with it and don't need aditional hardware. But its much more complicated to dial in really great sounds.
If the Amp sound is the most improtant thing to you, I'd go with the Kemper, since no matter how great an axe 2 patch sounds, a great kemper rig, sounds better IMO.
Stability is a main concern if you're planing to do midisetups of any kind, mostly a live problem atm. The Axe also has some crashing issues with every firmware. Just keep yourself informed online on the "dos & don'ts". (e.g. don't use "&" in a rig name )
Since the Kemper is the less expensive unit why don't you just give it a try? You have money back, so its no risk at all. (If the prices were switched, I'd suggest to try the axe first)
I can also pretty much guarantee you, if you take the time to get to know either of these units, you will be satisfied with either one. Since they're both great.
Either way, welcome to the board