I actually sold an ENGL Powerball to help fund my Axe-Fx purchase. I was able to pretty much exactly duplicate my old Powerball within minutes of hooking up the Axe for the first time. I couldn't believe it. Everything was there, the gain, the feel, tone controls that felt and reacted the same, the dynamics... everything.
I've never played an SE, but from what I understand, the SE is voiced somewhere between the Powerball and Savage 120 (both of which I have experience with), but favoring the Powerball just a bit more, in addition to having a lot more tone shaping options overall.
For a while, I was even considering picking up the SE preamp to run in the same rig with my Axe-Fx and VHT 2/90/2 just in case there was something there that I couldn't get with the Axe. That was way before the 7.00 update though. These days, I have basically zero desire to buy any type of amp or preamp, as it would almost certainly be totally redundant in my rig. The Axe-Fx is versatile enough that I'm totally confident that with an A/B test and some time to tweak, I could easily get close enough to the SE's sound that any differences would be negligible.
Honestly, now that I've had more time to tweak my own sounds and really hone in on the "tone in my head" or at least what I would imagine the type of tone people who want a Powerball in the first place would be after, I'm a lot more satisfied with the Axe-Fx that I ever was with my ENGL.
edit: Just as an afterthought... get the Axe, seriously. You absolutely will not regret it. Not only for the super duper ENGL style high gain stuff, but for everything else as well. The thing sounds great. I've shown my rig to a few people who love tube amps all around, as well as music store employees I know who are around quality gear all day long. Not once have I ever received a single negative comment or critique or "if only you could do this or adjust this little bit here" on the tone. Actually, as soon as I show most of them what this thing can do and sound like, and sit them down with my guitar and tell them to let loose for a while, they'll usually sit there and jam until somebody comes up and starts asking them about it.
In my experience, if the gear is good, it's easy to lose yourself in it. I could lock myself in the room with my rig for a day and be perfectly happy... I can honestly say that this is by far the best musical purchase I have ever made and I smile every time I turn it on. I know that sounds like a cheesy commercial or something, but it's true.
