If I know the author, I don't care about betas, but if it's someone I don't know and looks sketchy, I almost always won't. I know that can hurt me in return since I don't always use betas, but, well, you have to narrow things down somehow.

I get nervous if there's too many betas, though - quantity does not equal quality - or if the betas are people I know can't spell/write/etc. That's a detriment to me, because it implies there won't be much of what I consider beta work done.