It was gentle and uncomplicated and warm and I sort of loved it. I loved that the author wrote Luke's casual self-destructiveness with such compassion, and kept Russell so strongly in character throughout the book.
Possibly the other best thing about it all was that Luke was still the same enormously flawed character at the end of the book as he was at the start. Isn't it lovely that he stays himself? That realising he loves Russell, and having Russell love him back, doesn't make him worse or better as a person? Just that it makes him happy, which is enough, which is exactly what love should do -- and does so beautifully in this book.