@gmichelbkk - This is all very good information, but I think delegators need to seriously consider not only the returns offered by various bots, but also what type of content those bots are upvoting.

Some of the bots which are lower down on your list have lower returns because they are much more aggressive in blacklisting abusers and have settings that help prevent spam. 

Blacklists are typically not public, but before delegating to a bot I would ask them about their blacklist. Many on the top of the payout list have none, or very very small ones. Additionally it's important to look at the minimum post age allowed, which is published on https://steembottracker.com.

Bots that allow posts to be upvoted at less than 20 minutes open the door to lots of spam as users can just wait until the bot is about to vote before they post so that they can earn a large return by avoiding having any curation rewards taken out of the vote value.

There's a new site http://isteemd.com which does a good job of incorporating these factors as well as many others when determining which bots to delegate Steem Power to.