Sharing experiences with sponsored post networks

Curious what folks have found the best networks for joining up advertisers and publishers for sponsored posts?

I've been experimenting a lot with this (both as an advertiser AND publisher) so I thought I'd share, but curious to see what experiences others have had.

- socialspark.com: they're strict on the publishing side and opportunities can be hit or miss - better deal for advertisers I think.
- ebuzzing: tried a couple of times, can never get account confirmed. Whoops
- teliad: not recommended! terrible website interface, no support.
- payu2blog: liked their branding, but it's a "don't call us, we'll call you" sort of thing regarding approval of your account. I never got the call!
- linkworth: reasonable prices, format, good inventory on both sides. My fave of the bunch.
- webtrafficcontrol: looks great, although they haven't launched yet, very intrigued.
- verticalblogger.com: used to be great, but wondering if they're closing as there has been little activity in the last couple of months?

Publishers, what have you liked for sponsored posts? Advertisers, please weigh in!