I enjoyed the vast majority of this book, but felt that it severely faltered towards the very end.
My first criticism is, whilst I appreciate it is a book written for children, it is for the young adult age range and therefore feel that it still should have had at least one of the central trio dying. Secondly, the epilogue was way too saccharine and too neatly tied up - what are the chances of all those characters having offspring at pretty much the same time for a start? I also would have liked to have known what had a happened a much shorter time afterwards involving the world attempting to return to normal as possible etc.
Whilst the amount of time focussed on camping has been criticised, I felt it was important. Harry has so often just rode on the coat tails of others, it was good to show him bewildered, struggling to understand everything & the level of frustration shown by the trio. I am glad he did not miraculously figure it all out in no time at all, if you think how many people had dedicated so much of their lives hunting the hallows for example, it would have been insulting had he discovered both those and the horcruxes too easily. I particularly liked what happened when they opened the pendant horcrux, though was greatly disappointed that it wasn't followed up on more - Ron must have felt all those feelings festering for so long and yet instead we are supposed to believe he was really upbeat afterwards? I guess it's because I always expected Ron to be tempted to join the death eaters, that all the resentment at constanly being in Harry's shadow would be too much.
I was glad there was the break away from the huge battle to allow for Harry to discover the real Snape, though did feel cheated that there wasn't more time allowed for Harry's reaction to these revelations. Plus to see that in some ways Snape was more human and caring than Dumbledore was a brilliant twist. Dumbledore wasn't even certain Harry would figure out the deathly harrows and yet he happily set him up to face his death, to know that there was a darker side in Albus' past and that it continued to a certain extent until shortly before his death (him seeing the ring purely as a hallow rather than a horcrux to be destroyed) really did show such flaws in his character that had always previously been made out to be too good to be true.
Overall I felt Voldemort was shown to be a total coward, especially not directly taking part during the Hogwarts battle and keeping Nagini protected. The killing of Voldemort was admittedly incredibly disappointing, to think he had such a reign of terror for so long and yet it was ended like that .... but then it had to be Harry who was given all credit. Am I the only one who wanted Neville to be the one though? Wouldn't it have put such a spin on it all to discover Neville was the one the prophecy had referred to?
I have so many more things I meant to comment on, but they seem to have left me for now. I will no doubt post again later with more thoughts.