The writing is fantastic and I loved the witty banter between the characters. The love triangle that emerges is so unique and is more about getting over a first love and all the feels that go into that and less about choosing the perfect boy.
Death is never easy but this series presents an interesting view of both sides of it. You have the Post-Shifters who can see the ghosts (people who've died yet failed to pass on) and the ghosts themselves who are able to communicate with the living. There's the battle of good versus evil and for some of these characters, that battle is fought within themselves. (selfishness vs. selflessness, bitterness vs. forgiveness).
To me, this story really isn't about ghosts. It's about love and friendship, focusing on the important things and learning when to let go. I liked the idea that by not "passing-on" right away there's a window of opportunity to tie up loose ends, say what you didn't say or make amends but in real life, we don't get that second chance. All we have is the here and now and it too will be gone one day. The only thing that ever truly lasts is love.