I've been playing this game for about 60 hours or so, and just finished Chapter 7. Here are my thoughts on it so far.
Gameplay: It improves on Xenoblade Chronicles so much. Array of new weapons and combat systems.
Weapons/Classes: The weapons seem similar on the surface. Close range and long range. However, the arts that are attached to each weapon are unique and give each weapon its own role. For example, the shield has a tank role, the knife a debuff role, and the dual weapons a DPS role. I really can't decide which weapons to take in the end. There's just so many options. You can even mix and match the weapons after you max out a class branch. Right now, I have the Assault Rifle and the Photon Saber, and I've been getting so much burst damage in.
Combat System: As you progress through the game, you get access to more layers of combat. Secondary cooldown, overdrive, augments, battle menu, soul voices. It keeps the game interesting. It gets deeper and deeper, but not too bad where I felt overwhelmed. They introduced what the game had to offer in a paced manner, and the mechanics aren't necessary to enjoy this game on the surface level. Invites the casual and min/maxing players.
Story; Not much to say right now, since I'm not done yet. It's not as engaging as the previous game, but it's still slightly enjoyable. One thing I'm bugged about is how we're restricted to Elma and Lin for the story missions so far, and it doesn't seem like they're going to lift that anytime soon. I wish I could play with more characters during that time, but it's not that major, since I spend much more time doing missions and quests, which i dedicate my other members to.
Characters: I have 16 characters right now. Each of them has their own personality, although some may seem shallow at first. I'm pretty impressed how many different characters you can get, and how they're each very different. As you play with them, your affinity between you and the character increases, opening new affinity missions that help expand on that character's personality and backstory. Some standouts include Hope, Irina, and Lao. Some characters i dislike are Lin, Tatsu, and L. The others I am okay with. Some downsides to them are that you're not going to have enough time to play them all and have them at a reasonable level. Some characters you get at level 13, some at level 24. You forget about one of them, and they're not usable until you grind them up, which can be tedious, especially with so many characters. Another one is that they can only have affinity with Cross. The some of the characters just won't have anything to do with another. Also, because of this, you cannot switch out Cross. I'm happy they gave me such a wide variety of cast members, but Cross does not have a personality. Self-inserts aren't interesting. Also, most of the characters have very little impact on the main story. It's more like Cross, Elma, and Lin are the only main characters. Everyone else sometimes helps out, depending on who you bring along, but most are benched. It's disappointing, since XC had all playable characters with a stake in the story.
Specific Characters: Hope you get around the middle of the game. She is best girl so far. I like her giving personality and overall happiness. I wasn't sure about if I truly liked this character, but after the affinity mission, "A False Hope", I can say on no uncertain terms that she is my favorite character so far. That might change after I complete everyone's affinity missions, and complete the story, but I doubt it. I urge people to get to that affinity mission ASAP. Lin and Tatsu. Ugh. See, I wanted to like them. I thought I would like Lin. I wanted to give Tatsu a chance since I loved how they portrayed Riki in Xenoblade Chronicles. But, I can't say I enjoy them at all so far. Their whole shtick is that Lin teases Tatsu for looking like food. Lin at least has some personality in affinity missions, but when I see the duo interacting, I want to skip past it. It's becoming less of a running gag and more of beating a dead horse. Tatsu isn't even useful. He can't fight. Maybe he has some use later in the story, but man, I could just do without the two. I can't though, since they have a stake in the story, unlike other characters that I think are more interesting.
Soundtrack: I like it. It's a very hit or miss OST, and I can see why. It has a lot of vocals, specifically some rap. I'm not bothered by it, though it's understandable why people don't like it. It's way off what the original sounded like. Different composer, different setting. I think the OST fits fine. Some standouts to me are Black Tar and Uncontrollable.
This is just a sorts of rant. I don't think I could ever get my thoughts organized enough about this game to ever give a review I'm happy with. This game is amazing so far. I can't put this game down.