I don't rec stuff because I only read people I know (who tend to have enough other reccers out there) or off of recs (which means that by the time I read it, reccing would be superfluous).

Not that I'm saying you have to rec, but this isn't actually true. Every LJer has a slightly different audience, which means that recommending something you've seen elsewhere can actually be useful. I'm always surprised by the stories that get a "Wow, I'd never seen that one before!"

Mixing them in with stories without "warnings" would highlight the difference more than grouping them, I think.

I agree; I think a story that is, for example, un-beta'd would look worse in a set with three other incredible stories than in a set with others that also have great spots and bruises, so to speak.

If I offered recs in a different format - shorter summaries, different location, whatever - would they be useful to you? (Assuming, of course, that they're currently useful to you, which I don't know that they are. I only look at the aggregate data for my polls (except fill-in-the-blanks questions), so I don't know specific answers to questions unless someone tells me what she put.)