ABC search just re-opened up their advertiser thing recently, (a few days ago) so we will have to see.
Seek99, is an interesting one. Some people claiming to be former publishers have made statements about the webmaster being less than honest and encouraging fraud, though i dont know how seriously one can take this as it may be publishers kicked out for fraud trying to spite the webmaster.
What i do know is this, they claim on Alexa to be registered iN CA, when infact the webmaster lives in Portugal. Also they dont seem to have any sponsors except those provided by Kanoodle. What does this tell me?
ABC Search has converted well at times for me but it goes in waves...they will be excellent for months and then just garbage and high volume for a month. It's worked for me but use at own risk is a nice way to put it. I've never worked directly with Seek99, sorry.