Hello,
I have to write this post to introduce the 2.x branch of Google Ad Manager module because it is very convenient and handy even for the complex case.
The old version of GAM (and its brother, OpenAds) create a block for each ads slot. It was practical, but only for small sites. When you have about a few dozens of ad slots, and you want to use those blocks in Panels, or you want to place different blocks in the same place (depend on in which section user is)... it is a nightmare.
The new version introduce the "Superslot" entity. No more "block per ad slot"! Each superslot contains many ad slots, each ad slot has its own visibility setting. Even in a very big site with hundreds of ad slots, you need only a handy number of superslots, thus very easy to maintain.
Your feedback is welcome.