If you want my two cents, Takumi has lots of depth to him that shows he can be prickly at times just like his FE: Heroes mini bio says, but he's a good guy deep down who suffers from anxiety issues where he worries what others think of him. Sakura is shy, but she actually has a very strong will and is willing to take arms. Hinoka is a tomboy, but her struggles in becoming the Pegasus Warrior she is now put her in an interesting light that made me feel more sympathy for the character. Ryoma is who'd you expect for Mr. Samurai, but he is a great sage-like figure that can give great advice to those that need it: read his supports with Takumi and Mozu and you'll see what I mean.
Then again, I'm one of the few people out there who likes the Hoshido royal family much more than the Nohrian royal family. Camilla's Corrin-obsession and yandere attitude didn't leave a good impression on me. Leo and Elise are alright though, but I found them rather bland compared to their Hoshidan counterparts. Leo had some nice supports, but I couldn't sense as much depth to him compared to Takumi (Takumi felt more flawed, in addition to more relatable, while Leo felt more perfect; I'm more attached to flawed characters) not to mention I didn't like Leo's attitude to his son (he was a total jerk to Forrest in that Paralogue). Elise is rather too energetic for my tastes, to the point she felt like the more stereotypical loli compared to Sakura, and she had some face-palmingly foolish moments. Elise is a really likable character in Birthright though because they tone down her energetic attitude, and she actually makes smart decisions. I definitely liked Xander more than Ryoma though, and the reasons why is similar to why I prefer Takumi to Leo. Particularly, Xander felt more flawed compared to Ryoma, not to mention he was more relatable.