Re-watching is definitely better when you know what episodes to skip. I'll end up in a situation where I'll be like "I feel like watching this one!" or "I feel like watching that one!" and I'll watch it, and maybe a few, then I'm all set. So there's no realistic way I'd personally sit through 700+ episodes. I'm about to re-watch late-DS9 soon-ish. I say that and it'll probably end up being months from now.