I finished my book and thought it was fabulous. Having my family and some friends read it gave me some feedback, but it was mostly its nice, I like it, sign me a book when it's published. But none of the agents wanted anything to do with it. Then I joined a critique group and have gotten such good advice on how to improve it that I can't believe I thought it was good when I first finished it. I believe it was a good idea to let it sit and simmer for awhile and then come at it again with a new look and new advice.
I'm getting excited to see how to make it improve with each time I read through it.