^ I don't think you're alone in that. I love my Axe too and can't see myself going back to tube amps, but is it 100% the same tone and response, no. On cleans and just-breaking-up tones I find it pretty much perfect, but for that really singing high-gain lead tone there's just something about it that's not quite there yet. I feel like the more gain you add the more a certain 'Axe character' is evident, the unit itself has a subtle, but recognizable tone. I felt it more when I got mine first, I wasn't disappointed at all, but I did hear something in there, with the high end in particular on distorted sounds, that just sounds not-quite real. I think after a while with the unit your ears get accustomed to that and you don't notice it so much, especially when it's in a mix with other instruments.
Again, I'm not complaining, it's light years beyond any other modeler and I believe and it gets more 'real' on each firmware update. For that reason I'm delighted to see that development is still ongoing.
I think you could almost draw a parallel with something like video games. As each new console generation comes out the developers have more power to play with and they can use higher detail meshes and textures, and do more sophisticated lighting effects etc. And for each one there's a leap forward in visual quality that makes newer games feel more 'photo real' and suddenly the older games shortcomings become more obvious to the eye. Same thing with the Axe Ultra, a few years ago that was the benchmark and most users would have felt that it sounded very 'realistic'. But now if you listen to one beside the latest iteration it's pretty obvious how it wasn't nearly as close as the current one is. That process will happen again I'm sure.
