Just did 4 Ad companies, and working great Had 1 crash like wpd mentioned: Crash on Admob (inactivate other mediation to isolate), never successfully requested an Ad, Load Interstitial cause app to crash.
But it seemed to go away. so not sure if it's a setting. I had my Min Android version set to 2.3 vs 3.0
Since there are no Smartbanners, I was able to still have the Admob object on my frame to get the banners. Not 100% if they are becoming a conflict.. Then I might turn off Admod, just to keep the Smartbanner.. (if that makes a difference in the internal codes with those components, no idea).
Have tons of screenshots, so enough material for a guide