Person wants the job and preps for it to give themselves the best chance to get it and you’re looking for something wrong with them? I’m not sure I get it.
I always took notes to interviews. I knew what I was looking for and didn’t hesitate to follow up with e-mail questions, but it always helped to get answers in person.
For work I did I had an annotated copy of the CV I sent in for the job in case they wanted more examples. A lot of times, you can’t fit in everything you consider important on 2 sides of A4, and in an interview situation you may forget that you’d done something. This was a good hedge against that. In any case, you can always drill down into what they’ve done to see how well they know it. Notes aren’t going to help you there!
I’ve interviewed and been interviewed. Weirdly, I’ve not seen a single person who turned up with more than a copy of their CV to an interview. In fact, it’s more likely I’d see someone who couldn’t talk about what they’d bigged themselves up to be on their CV!