So the battle system in the series most closely related cousin is probably Final Fantasy 12. Which I thought was just terrific! The music is tops, some of the best in Nintendo's library - which says a lot.
The graphics are good! But sadly it can look pretty bad on an hd tv. I loved the story and the side missions to pieces, at least to a point. I won't spoil anything because some people really enjoyed all of the twists, and honestly there were a few that I did not.
On top of that I found that there were some puzzling difficulty spikes that didn't ruin the game (until again a point)
Overall it's terrific and worth looking into if RPGs are your thing.
As for X, it retains a similar battle system, but opts for far less of a narrative than its predecessor. I don't care for that format personally, but many people love the MMO/open world design, so is leave that up to your personal tastes. I would also say that there was some complicated menu finagling that I couldn't wrap my head around. Again, you know your tastes.
All that said I think the series an incredible piece of Nintendos first party line up, and an very excited for
Xenoblade 2.