Hilde, you're a reader of Janet Evanovich, if I'm remembering correctly, right? Have you read her latest, The Heist? I got it from the library, read maybe a quarter of it and returned it. It didn't hold my interest at all. But I'm thinking I should give it another chance.
I did read it and I agree with you: The Heist is not that good. I was disappointed by it.
The main letdown was that there isn't enough of the typical Evanovich tension between the two main characters. I did read the book to the end because I kept thinking that it would start getting better and it was just a slow introduction between the two main characters but it didn't quite happen.
I don't know if you know the tv series "White Collar"? It's got the main basic idea behind it with the difference that the book has a woman and a man as the two main leads whereas the tv series has a friendship between two men but the basic idea of a white collar criminal working together with an FBI agent is the same. The tv series does it better since the book criminal lacks the charm of the tv criminal. Janet usually is very good at this stuff but maybe it's due to her writing partner.
I blamed me not liking The Heist all that much on wanting to see the tv guy in the book guy, though. But if you didn't like it either, it's not just that.
In short: I wouldn't bother with giving it another chance.