We recently restarted our campaign with Yahoo after pausing our adds for the past two months.
We ran Yahoo for the first week by it self to get accurate conversion
It appears our conversion rate with Yahoo is about as good as Google.
There was a few adjustments that had to be done to my account to get it up and running, which a Yahoo rep worked with me over the phone to make the corrections.
I look forward to the quality traffic we will recieve from Yahoo.