I have been in this biz for a longtime and I have tried them all
SEDO=Garbage
Domainsponsor=Junk
Google=ok
Domainsite=Attrocious
Namedrive= Best revenue per click, nice designs available, EVERY VISIT is recorded unlike others ( right SEDO ), Fast Payments, All my domains were moved to Namedrive the first day they opened except for my portfolio premiums which I still use google for. But a majority of my names are at Namedrive and I am very happy with the service and overall experience with them. They also pay for foriegn clicks whereas the others only pay for USA. Namedrive also for some strange reason get better google results to. I have had several names at the other PPC venues and these names had no pagerank after a month or so these names were all listed in google search results and a pagerank was assigned, I even have one stupid domain with a PR 6 and for 3 years of parking prior it was a zero. most of the names once at namedrive for past couple months get a PR4
If any domainer with even the smallest amount of traffic wants to cover registration fee's and put some bucks in there jeans i reccommend namedrive.
And no i have no affiliation with namedrive other than being a very happy client