Full Disclosure: I f---ing love Xenoblade (although I haven't played X yet), and I'm a much more traditional turn-based RPGer primarily.
Xenoblade can be as difficult or easy as you want it to be. There's a metric ton of room for playstyle differences once your roster starts to expand, and if you're willing to put in the effort, you can unlock as much content as you want in one go around. While I normally despise MMO-style gameplay myself, Xenoblade does a really good job of balancing things out, and does get significantly more complex as things go on. If you don't adjust your strategies or overlevel, you will not survive later in the game.
That said, if you want to explore everywhere and do literally every sidequest as they become available, you will generally be overpowered and cakewalk through things. That said, the plot is good enough that I could even recommend that path too. And it has Dunban, which should be reason alone to get the game.
Honestly, Xenoblade was probably the last amazingly good, instant classic game I bought new, in just about every single way (I do honestly kind of hate the evasion mechanics though). Just get ready to hear the word "Monado" a bazillion times.