Haha... it's hard to search SitePoint for "media.net", the search seems to split it into "media" and "net"... which is kind of useless for search. I hope this hasn't been asked too recently.
I've been approached to try Media.net ads on one of my sites. I'm hesitant to spend the time (and missed AdSense revenue). I've tried a couple non-AdSense networks in the past, and they have proven to be utterly pathetic in comparison to AdSense. Of course the Media.net rep claims that they'll have "good CPM"... but I've heard that story before.
Anyway, I'm hoping for some advice from others. Have you tried Media.net's ads? It looks like they're contextual... is that still banned on the same page as AdSense?