I disagree with keyplyr completely. BAS/Ad Experience Report has nothing to do with MediaPartners-Google as BAS is not specific to Adsense and the bot only ever crawls pages that have AdSense code on them. Moreover, it only impacts the Chrome browser so it is specific to Chrome and my guess that the reviews are being from Chrome directly and apply to all ad-networks and implementations.
As for Page Level I see no harm in using them, they are well implemented and provide an additional means of monetizing mobile users, which tend to be more challenging. I see a higher CTR for the overlays than my regulars ads.
I am currently experimenting with removing adsense units and testing the effects of this on my position in Google SERPS. So far, the test seems to indicate that the number of ads in the html does impact the position of the the page in the SERPS.
I am still testing, but so far the test indicates that Google's use of measuring ad units as a ranking factor is not very intelligent - I have several ad units, but use .css and media queries to determine which ones are displayed. So far, the test seems to indicate that Google is not taking the css into account, but rather just counting the number of ad units in the html. Again, more testing is needed.
So far, the test seems to indicate that Google is not taking the css into account, but rather just counting the number of ad units in the html.