Thanks for your response! However the OP wasn't questioning the eheim.
I also have an engineering backgroun and have used all of the filters in question. If you want to spend extra money for no appreciable capabilities, by all means spend the extra bucks on the "E"s.
I feel it is inappropriate to rate a specific brand better than others when you you haven't used them. It is okay to state your opinion or repeat someone else's experience, but to claim the one is better than other's without personal experience is a bit mis-leading.