I really enjoyed this book, at first I found it quite slow, but somewhere towards the middle everything started to take shape and the story began to pick-up. Even right at the end new pieces of information came to light, which I loved; it completely changed my perception of Grace.
I agree with a lot of the criticisms mentioned above. The biggest issue for me though was the similarities between this and The Blind Assassin by Margaret Attwood, which I found quite amazing!!! Although The Blind Assassin is probably a better book from the point of view of a literary critic or anyone that knows about books, I think I enjoyed The House at Riverton more. This is mainly because although it could be seen as a shortfall that certain parts of Grace's life were left undeleveloped, I think it would have been boring to give that kind of detail, I feel a bit guilty admitting it, but I didn't care that much about Grace's life post-Riverton and pre-old age and I was glad I didn't have to read too much detail about those years. It also allows the reader to use their imagination a little to fill the gaps...
Bit of a babble, sorry!