I love them with one caveat.. I now have the apex AFS. Previously I had an eheim. The only problem I had with my eheim that made me upgrade to the afs, was that the motor on the eheim stuck and emptied all the food into the tank. I have only had the apex unit for a few weeks, but it has been an awesome tool!
I feed them 4x a day with small amount of pellet(nls) given. I also feed a small amount of frozen once a day also.. But if you have a controller(apex), it is well worth the investment..