First off, I have to admit that I wasn't jonesing to watch this movie. I wasn't a huge fan of the books - I only read the first 2 and while I thought they were fun enough, Becky's irresponsibility annoyed the crap out of me. My gfs basically finangled me into watching it with them by buying me a ticket without telling me. And, I did like Isla Fisher in it (even though I wish Becky had been portrayed as British), she's adorable.
But I thought the rest of the movie was terrible! I hated the way they totally reworked the story. I hated that they made Luke her boss, and that Alicia wasn't really his girlfriend. I hated that they made Smeath (the collections guy) out to be the bad guy so it was okay that she paid him back with pennies, when hello? She was the one who was waaay late on all her payments, it's not his fault she dodged his phone calls for months! What else? Seriously, everything but Isla Fisher bugged me.