I use them both, and it really depends on the URL.. Lets just say using Amazon.com and if no one was bidding on that URL or you were the #1 bidder.
Id say Traffic Vance gets about 2x the amount of traffic then Media traffic.
And Zango 4x the amount, linksador about 1/3 the traffic.
But i love the interface of Traffic Vance alot easier to use, but then again really a users preference.