I had an ADF with my Angel. It recently died of unknown causes. I will tell you though, it was very tough to get the little guy to eat. My local fish store recommended sinking pellots but he wouldn't touch them.
I never had a problem with him escaping because I kept the water level down about an inch and lowered the cave so he couldn't jump out. Now on the other hand, I just purchased two spiny eels that have escaped and we didn't find for about 5 minutes.
I never had him climb out of the filter intake tube. He pretty much just hung around the bottom. The eels are good now. They were out of water for about 5 minutes before we found them but they are fine. We were changing the rock bottom to sand and that's how they escaped. The pet store told me they wouldn't escape but boy were they wrong.