I don't think you or anyone will be disappointed with the quality of the screen on the 600. It really is nice and sharp. Unless you have it sitting right next to the 505, you wouldn't even know that there's anything better. I just happened to have them side by side so could tell the difference.
I didn't test the notes and highlighting, but from what I've seen/read online, it looks like it'll do that great.
Yep, it was just a camera in my phone, so none of the photos came out very clear or sharp, hence the blurriness.
I didn't actually take any of the 300 though did have a pink one on hand. I should have thought to do that. Whoops.
If I'm by there on the weekend, I'll try to remember to bring my point and shoot to take some better ones.
Oliver