OK, Fractal forumite ethomas and I got together last evening to A/B the two units. ethomas is a good guy and I’m very grateful for his generosity of time and his willingness to come help me check out the two units. We did, indeed, have some really cool guitars to play with. It was fun.
I fully expect to get flamed by both camps, but I’ll start with the bottom line and then unpack the thoughts a little bit. Here’s the nutshell: both units sound incredible. Truly. They both sound and (just as importantly) feel like a legit tube amp. I don’t want to speak for ethomas but I think we both agreed that either unit would be very usable and that either of us would be happy with either one. That’s all. No qualifications. They both sound/feel fantastic. Note that both were on the latest firmware...3.0 for KPA and 18 beta for Axe-Fx, and both were played through an Atomic CLR Neo Wedge (great FRFR, incidentally).
Keep in mind that the last time I played through anything digital, solid state, or modeling-related was back in the Digitech RP series days. Those things sounded like crap and made everything sound overly digital. We’ve come a long way from those days and I could honestly use either of these units and be content.
Here are some more specific thoughts:
Tone - both sounded good. Really good. They both had some tones that were much better than others, and again this will be affected by the individual player, guitar, and so forth. For all of the talk by some of the Axe being hard to dial in (because of too many options), it really wasn’t hard to dial in a usable tone on either device. And both devices had some default profiles/models that just didn’t sound that good. I’m not so much concerned with how accurate to the original amp the sounds are (unless I’m trying to capture my own amps, in which case I’m VERY concerned with that); I’m more interested in whether they sound good and are usable tones for me. Both definitely had that in spades.
Feel - both feel really good, respond well to finger dynamics, how hard you pick, etc. Both respond well to volume and tone knob adjustments. I’d give a very slight edge for “feel” to the KPA, but it’s almost imperceptible. They both feel great. No hesitations about this at all (this was one of my worries going in).
Usability - both are really easy to use. If you’re going into really deep parameters and messing around with them, then probably either device could get tedious or complex (esp. the Axe because it has more options). But just pulling up profiles/presets/whatever is easy on both. I’m far less concerned about this than many people seem to be, because I’ll get accustomed to whatever I end up with.
Effects - this is the only place, IMO, where there is a clear win for either unit (unless you’re comparing just a flat number of features). The Axe’s effects sound more natural, there are far more of them, and there are a lot more options to configure them. I don’t use a ton of effects, so this isn’t necessarily as big of a deal for me as it might be for others, but even the two effects that I almost always use (delay and reverb), the Axe wins hands down. The biggest place where this was noticeable was in the decay of the delays and reverbs on the Kemper...they sounded very digital and non-natural - not drastically so, but noticeable. The Axe’s were really nice. I don’t think the Kemper’s effects sound bad; they are very usable. But when you compare them, they just don’t stand up to the Axe’s. Also the routing options in the Axe-Fx DO make a difference. Sometimes I want the delay early in the chain, sometimes at the end, etc.
Conclusion - So, what’s my choice? I’m actually still not 100% sure. That’s not a cop-out; both units are awesome and could work for me. I think given the parity between most facets of the units, the one thing that stands out is the effects on the Axe. For that reason alone, I’d probably choose the Axe platform over the KPA. I could certainly use the KPA and then just use another effects unit, but I’m trying to eliminate as much gear as possible. All things considered, my ideal solution would actually be something like the AX8. If that was coming any time soon, it would make the decision pretty easy, and it also combines the foot controller with the modeling and effects. A couple of trade-offs, but for me they would be easily worth it. So, at this point unless I hear that the AX8 won’t be out for two years or something, I’ll probably wait for that to release. If it is going to be a while before it comes out, then I’ll probably go with the Axe-Fx, simply based on the effects capabilities.
For me, this is not a win-lose situation; we live in a great time when there are fantastic devices like these that make the choice between them really difficult and really just come down to what works better for each person, based more on minor usage factors than any major or overwhelmingly lopsided difference in quality, etc.