i have a mainstream aff program i send traffic to...i use google, findwhat, goclick and have used search123 and kanoodle in the past for testing. my results:
google 1:20
findwhat 1:30
goclick 1:50
search123 1:333
kanoodle 0:1000 LOL
draw your own conclusions
getting ready to test searchfeed right now...heard okay things about them...