The Mystery Factor

I have found that writing a mystery/suspense novel has proven to be a lot harder than I had originally anticipated. Trying to keep the basic story line with the twists and turns of a mystery while also creating personalities that readers can relate to has become quite the challenge. I find it hard to keep the balance between the two. For those of you who have read some of the story, I would welcome any feedback, either positive or negative. I would love to hear what anyone has to say. Every opinion matters.