Thoughts/Opinions on Mobile Exchanges

[beashmm]

Hey Mobil Marketers,

Wanted to know if anyone could give a description of each of these mobile exchanges, what's different between them, if it's quality, more app or mobile web, more english or not, etc..

OpenX
TapforTap
Rubicon
MoPub
Smaato

Thanks for any thoughts,

Cheers!