http://www.digitaldjtips.com/2012/12...-review-video/
It's not that it's not a Pioneer that's the problem, it's that it's a pair of CDJs full stop. If I had $600 to spend, I know EXACTLY what I'd spend it on, and there wouldn't be a CD slot in sight.
EDIT: To be more helpful and less sarky, aside from "it's a CDJ", I don't have any particular problem with the CDJ700s (or any derivative product), apart from the ridiculous screen on them. It's a PORTRAIT 240x320 screen that looks like it's been pulled off one of the old Series 40 Nokia mobile phones. If you're planning on a) mixing by ear, or b) using it with Traktor/Serato/VDJ anyway, then just ignore the screen.