If u have a site that gets lots of traffic, go with banners, if u have a blog or something that gets very little traffic, then go with text ads.
Advertiser who use banner pays more than just a link. But then, banner normally get lower ctr. End of the day is about the same. Track n test which is the best for you.
If you want to know what ad people click on - setup a separate custom channel for each ad and then you'll see reporting for each channel, which is practically for each individual ad. To setup custom channels it's at the bottom of the ad settings page, "All channels" and there is "Add new channel" link. I use it a lot - it helps me to determine the best positions for ads on the website. GM
From my experience, text ads pay A LOT more: as long as they are high on the page (not at the bottom of the page). I experimented with banner ads a lot, it's nowhere near in $ terms compared to text-only ads..
1) Banner ads normally pay more, but generate lower CTR than text ads. 2) The best option is to leave the option of both banner as well as text ads, so that Google can select right option for you based on the content and visitor.