Maybe it's because I'm not too attached to the Fire Emblem series, but I thought this game was incredibly underwhelming, especially after all the recommendations I got from my JRPG friends.
Tokyo Mirage Sessions #FE is essentially a Shin Megami Tensei game with a music/entertainment industry flair to it, one that seems to overpromise and underdeliver a "Fire Emblem crossover" experience.

That's not to say this game is bad or anything. There are several things I enjoyed about Tokyo Mirage Sessions. The highlight for me personally was just the overall style and presentation of everything. It's a story that takes place within the industry of music and film, so it respectfully plays along with that here. Everything from the dungeon designs for each character, down to the session combos being represented as music tracks, it's all a fun topic to surround a JRPG into. And speaking of music, the soundtrack here is excellent, most of which are accompanied with some stunning 2.5D animation in music video-style formats. It all feels like a halfway step between Shin Megami Tensei and the hyperstylization found in Persona titles.
As for the gameplay, I'm a big fan of the implementation of session combos, allowing you to fully stack party attacks onto enemies once their weaknesses are exploited. The dungeon designs each have their own unique quirks to them too, some of which I personally thought had some neat puzzle-solving elements. And, although understandably ignored by hardcore players, I appreciated the inclusion of the Training Area (which I understand was DLC in the non-Encore version), as it really saved me some time with grinding points for my party and equipment; a necessity for a Shin Megami Tensei game of this nature.

The rest of the game though? It's a bit meh.
I could honestly care less about the story, because most of the characters arcs are predictable in how they resolve themselves. They aren't boring or anything, just not my personal "anime"-esque plot to devour, although I did like some side stories unlocking more of those awesome music videos to watch. As for the Fire Emblem crossover, like I said, it's incredibly underwhelming. As someone novice to that series, all I really noticed were the Mirages being named after certain characters from Fire Emblem, and only the last handful of hours of the story really diving into lore from that series. I just wish we'd get a bit more of these elements earlier on and spread throughout, as it just makes this game feel like an SMT spin-off with nods to Fire Emblem and that's it. A lot less than I was expecting from a game published by Nintendo themselves.

Tokyo Mirage Sessions #FE is a good JRPG, although I can't really recommend it to fans of the genre. Unless you really enjoy Fire Emblem or Japanese pop music, or are looking for a decent 30-40 hours to dive into, I say you can pass on this one.

Let's start off with the OST being unironically the best in the series. Reincarnation? BANGER. Feel? BANGER. Give Me? Labryinth? Dream Catcher? BANGER after BANGER. I literally felt more emotion listening Opera of Light then the "Everyone is Here" trailer. This OST gets played in the car, no exceptions.

This game is the epitome of "this just feels right". It got the perfect amount of quality of life features to keep me enjoying myself. The weapon upgrade system is not complex and easily usable throughout the story (unlike Fates). Combos in combat (taken from Persona) stays fluid through the story. Achievements aren't generic (Engage) and don't get tedious (Three Hopes). Also has a functional New Game Plus mode which I hope stays a standard in the FE series.

The characters and story don't fall short either. Each member of the main and supporting cast gets their time in the spotlight while staying relevant through the rest of the game. The mirages don't take the spotlight from the original characters but get used to bring out the characteristics in them (better than Engage's way). The story of TMS existing in the universe where Marth failed to destroy Medeus makes this more canon than the other spin-offs.

Overall this game has everything I could find enjoyable without any negatives. Full remarks.

The characters are eh, the story is just kinda ok, I don't have any interest in idol culture so none of that stuff really captured me, and this REALLY has no right to be an SMT-FE crossover, and should've really just been marketed as its own thing under the Tokyo Mirage Sessions name, and its a shame it wasn't because if it was it could've been picked up for sequels under its own IP, because GOOD GOD this game SOMEHOW may have the best gameplay of ANY SMT branch. The combat all flows together so nicely and is honestly the best execution of the SMT gameplay formula I've ever experience, granted as of this point I've only has the most basic SMT experience (persona 3 through 5, as well as SMT 3 and 5), but I'll be damned if I wasn't getting into encounters whenever possible just for the sake of doing the combat more.