The extra star (my fairly rare fourth star) for this last item in the Harry Potter series reflects my satisfaction at a successful wrap-up of what had become by the end an exceedingly complicated multigenerational tangle of motives and magic. Just as we had the explication of Voldemort's past in Half-Blood Prince, we had a lot of visits to the past lives of Dumbledore and Snape here. However, I thought these inset narratives were a bit more gracefully handled in this novel.
That said, I'm not entirely convinced it was necessary to introduce an entire counterquest (the "search for 3" - the 3 Deathly Hallows artifacts that conquer death) in addition to the completion of the main quest (the "search for 7" - the 7 Horcruxes, including Harry himself, which contain the evil which must be killed). Just as Harry's self-immolation seems a bit redundant when we've already had Dumbledore's on the same altar, so too the extra quest seems rather heavy freight just for the sake of reinforcing the theme of the novel - that evil, not death, is the ultimate enemy.
That said, the King's Cross Station out-of-world vision was well worth it - quite probably the most affecting scene in the entire series.
Rowling takes us back to ground zero, Hogwarts, for the final battle between good and evil. I resented this slightly - as I had already been doing in some degree since Order of the Phoenix - as Hogwarts' safety and impregnability crumbled completely. There's something very distressing about a school that's not safe, especially when you have an author who, like Rowling, doesn't flinch at killing off her secondary leads.
Even had we not had Rowling's later clarification in an interview, I would have suspected that Dumbledore's infatuation with the evil wizard Grindelwald had a sexual element to it. But this comes from someone with a half a century of gleeful subtext detection under their belt.
I found Ron's desertion of Harry and Hermione when they were doing their enforced and very bleak on-the-run camping trip a bit under-motivated, but I was glad to see him return in a blaze of quasi-heroic glory, rescuing Harry from strangulation by a magical nasty in an icy pond. If there's a character-based summary for this novel, "Ron grows up a bit at last" might be it. I don't have problems with the Ron/Hermione pairing, but I am a little surprised that Rowling chose to pair Harry off as well (with anybody at all). I'd expect him to be noble and single, as Dumbledore was. Nonetheless, for me, the much-maligned epilogue was a matter for a shrug; why not give the main characters a mundane domestic future as a reward for surviving all that trauma?
It fascinates me what a massive influence this series has had on the popular culture of a generation a couple of decades behind mine. I was trying to think of a similar phenomenon for my own generation, but even "Star Trek", with all its well-known characters and catch-phrases, doesn't seem to me to have penetrated into all corners quite the way Harry Potter has with the millennials. I enjoyed the reading of this series purely for its own sake - I hope I've made that abundantly clear - but I also think I'm now going to reap the ancillary benefits of understanding what is almost a second language of allusion and emotional shorthand.
I'm not sure I would have enjoyed this experience (or not in the same way) if it had been spread across the decade of the original publications, with a new thick book every so often. Having it all focused into a few weeks, and through the rather sensually barren medium of an e-reader to boot, was, I think, the right way for me. Definitely one my most delightful reading projects of the last few years.