I'm at close to 30 hours now, and in the Makna Forest. I was still working on quests in this area when I stopped playing on the Wii years back, so I'm just about caught up to my first (unfinished) playthrough.
I'm having a great time with this game. I'm completing every single quest as I go along, so I'm spending big chunks of time in each area. I never get tired of the music, especially with the different day/night versions, and DAMN, the locations are so beautiful. I've taken a ton of screenshots of waterfalls and cutscenes, because I somehow always hit the cutscenes at night, when the sky looks amazing.
I don't remember enough about the mechanics or UI to speak much on the upgrades made to this version, but it all feels pretty seamless. There are a lot of helpful menu shortcuts: left stick to expand the map, Y to open the map areas, down on the D-pad to open quests, X to close all menus without hitting B multiple times.
I still really love the Collectopaedia, and the armor appearance options.
One thing I'm not sure would appeal to everyone is a certain aspect of the battles, which is the auto-attack. I was asking my boyfriend if he thought he'd want to play XC, based on the bits and pieces he's seen. He said the plot sounds interesting and the game looks really nice, but he was wondering about how active your role is in battles.
Simple explanation: yes, you auto-attack, but you're also actively moving, selecting arts, and strategizing.
Longer explanation: You have the Monado abilities to consider, like using a Shield if the enemy is gonna use a powerful attack, or Enchant if you're fighting mechon, because your party can't hit them otherwise. You're also moving around to use Arts that do more damage from the back or side, and paying attention to HP. You also want to focus on whether you've used Break on an enemy, to open it up to a Topple from someone in your party with an appropriate move, and then a Daze attack once they're toppled. You're also keeping an eye on the Party Gauge, so that you can use a chain attack when it's full. Shulk is simply auto-attacking at a set interval in between you doing all of this.
This might make it sound way more complex than it needs to be, but once you've got a handful of battles under your belt, it goes quite smoothly and it's really not difficult to manage. Point is, if you were also having to press A to do a normal attack, it WOULD get frustrating. I'm glad it's set up the way that it is.