As far as tone goes it's all a quite personal thing.
The main thing to keep in mind with modelling amps with loads of digital effects is whether or not you are comfortable with the interface, and whether or not the interface will allow you to achieve the combinations of effects you desire. For instance some amps with foot controllers have only 1 foot-switch for "od/dist/fuzz/boost" but their may be applications where you'd like a boost and od, etc at the same time. The same goes for volume/wah, chorus/flange/phase/uvibe, etc etc.
Just make sure you are happy with the tone, volume, and interface...especially the interface and tone...you can always mic an amp to play a gig assuming the PA is good enough.
I haven't been a big fan of the modelling amps that I've tried, I prefer stomp boxes into a nice all-tube 2x12 combo. High volumes can be an issue with this set-up.
I was using a Vox Tonelab and foot controller, which I was happy with for recording riff's and ideas on my home computer. I tried a couple of demo's with it but found allot of the tones I liked to play with didn't really sit nicely in the mix, i am however not a recording engineer so that may just be my own incompetence.
What I'm getting at really is for practising and convenience a modelling amp or unit is probably a great solution.