I think the Ron and Hermione romance worked as a classic trope of rivals-turned-lovers and all that jazz. I have no issues there. Other than that, romance has never really been Rowling's forte and there's something so hollow about how it's written that it comes off as sterile and sexless as all hell, which is surprising since a recurring theme of the book is growing up.
The only character I feel is truly worthy of any praise is Snape and I hate how he's been twisted into a shitty Nice Guy trope over pining over Harry's mom. The guy was a dick but he wasn't a fedora tipper. Just a bitter, nasty, broken person that knew he made mistakes and wasn't sure how to correct them. If there was one positive thing I could say about Rowling was that she understood (at least at the time before lousy twitter politics made her worse) that often the nastiest people do what they do out of hurt or regret and can still be a hero even if they're not the best people.