The Hagen Aquaclears are the best HOB filters I've ever used. They put out great flow, are silent and run forever. I use them on my nano tanks to create flow without adding heat to the tank. I have one that's been running nonstop for almost 6 years. (Except for about two years ago when I finally removed it to clean it) Haven't ever cleaned the new one on another tank, it's been running for 5 years.
FYI, I don't use the filter media, they're filled with live rock rubble. Once in a while I'll drop a bag of carbon into one but that's only if things don't look right.