It should be above 40%. Still, the new Ads by Google button gives me a nice idea for blending. Gotta start split-testing again :/
I dont like this new format, the ads are better visually but now will be most evident for the visitor that its an advertising block and the CTR will be drop in my opinion.
These new ads are a lot nicer. The old ones seem so ugly compared to these. These have a smoother look to them.