I own CAE the fish isnt as big of trouble maker as they sound. But its true they do get lazy.. but lately mine has been doing some cleaning Yes they do try to suck on other fish but not alot. I think CAE are fine but SAE's are better when it comes to cleaning. CAE's are interesting fish
SAE's will definitely eat sinking wafers (both algae and & bottom feeder tabs).
I'm not sure about SAE's attaching themselves to other fish. Mine haven't, and I'm not sure how well they're equipped for it. SAE's
don't suction on to what they're feeding on, instead they 'hover' by swimming against the current. Though I have seen my SAE's hang on to the side of the tank, only rarely when they were resting and never while feeding. I've never seen them scoot around along the glass like Ottos do.
Yes they do try to suck on other fish but not alot. I think CAE are fine but SAE's are better when it comes to cleaning. CAE's are interesting fish 
