For recording it's cool. Unless you want a signal chain with wah after dirt, compression after your amp model, or something like that. For most "normal" chains it should be fine. Download the manual first (you may have to create a free Line 6 account) and read it
Live, just remember to turn off the cab modeling, and it should sound better. I think there might even be a mode for this.
Pricewise, I'd go used. New xts should be at least half the price of the X3, since the X3 is just 2 xts in 1 box. The last time I checked they weren't
