I use both Sedo and AdSense for Domains. AFAIK both are snoozers (that is, they'll put you to sleep). Sedo landing pages are a little more colorful and original. AdSense is dull and uninspiring. Maybe Google has plans to make them more inspiring, but until they do, I'm not impressed.
Parking pages are usually uninteresting, so I don't put much hope in them earning significant money, either Sedo or AdSense. I have some pretty good domain names using both systems. Even my good domain names don't earn a lot with either system. There must be a better way.