For contrast, I happen to really like the flavor and I'm really glad that WotC is both pushing the envelope and that they're pushing it in this direction.
Specifically, I appreciate how they're explicitly calling out a lot of different magical academy tropes AND addressing school-based tropes in general. Remember, the Tolarian Academy was a bit part of earlier sets! I'm willing to bet that one could make an entire set out of Tolarian Academy-themed cards if one is willing to ignore color balance/playability. Magic schools are actually a very diverse bunch (Faerun and D&D's schools of magic, Brakebills from The Magicians, the school from A Wizard of Earthsea, the University from The Name of the Wind, and lots more--this is just what comes to mind.) and I'm seeing elements of all these and more, so I think it's not really fair to call it 'just Harry Potter Universes Beyond a year early.'
In terms of tone, I appreciate that WotC is willing to explore sets that are location-based, not crisis-based. It gets really tiring to have Our Favorite Planeswalkers Save The Day In An Exotic Location all the time. This is one of the reasons why I've soured a bit on Marvel movies, but maybe WotC is conscious that people get tired of this? I never want to give them too much credit. I'd love to see them continue to explore more personal crises, like how Liliana deals with guilt, an emotion she thought could never affect her again after her brother's gruesome fate.
Sizing of creatures has never been a big issue for me personally (Squirrels, Emrakul, etc.), but I totally see how that would be incongruous for other people.
I do have an issue with this set so far, and it's that the cards are incredibly wordy. It's not the sort of wordy that's just legalese to describe an intuitive effect, either. The Deans in particular are especially offensive to me--part of my attraction to MDFCs is that they should be easy to parse on both sides.