I think this is a smart move by the company and I like competition. I know they are in the early stages of the program, but there are more features I would like to see before jumping in. Presently, my ad network of choice is Google AdSense for various reasons:

1. speed (if you ~don't~ enable all their 3rd party networks)
2. international coverage
3. all IAB ad formats
4. ability to disapprove ads / categories

I'm also one of these people that doesn't like ads to interfere with the user's reading experience. From that standpoint, I wish I had more control where I could place the ads. These early options aren't the best for my users, but I will definitely watch this space as I'm also an ad purchaser. It's also an interesting time as publishers are experiencing a drop in revenue because of ad blockers, which I understand. Many sites put revenue ahead of user experience.