Speaking as somebody who loves my Axe-Fx 3 to death... if I can give you a piece of advice, it's that even if you can dial the Axe-Fx to sound as good as, or even better than, your tube amps, I'd keep the tube amps around. If you're like me, you'll still want to fire them up every now and then for one reason or another. For one, tube amps are just cool. They're big heavy wood and tolex boxes that get hot and smell like electronics and heated up dust, and there's just something awesome about playing through them. There's a part of your brain that's aware of the analog circuitry and burning tubes that are using their "fuel" as you play, not unlike a race car. I dunno, for me, there's just something about simply knowing I'm playing through analog gear that gives me the fizz, even if it's only a placebo, lol.
A modeler has its own benefits too, but that analog part of the experience is impossible to replicate. Also, you know your tube amps are the "benchmark" tones from which the models are derived, and it's good to have them around as a kind of touchstone when you need them.
Play your Axe-Fx, learn everything it can do so you can squeeze as much out of it as possible, but keep the tube amps around too.