Sleazy,
I review both of these PPC services on my website:
www.PPCIncome.com
In brief, I have received consistently better revenue at Fabulous.com. The few domains that have done well at Sedo are those that do best with UK advertisers, as Sedo is strong in that area. I do even better with Domain Sponsor. There is a fairly extensive review on each of these services, and more, on my website.