I've been running a Deltec 702 for almost 8 years. I have had 1 pump go out in that time frame. I only clean the pumps and body about every 18-24 months. I pump 500mg/hr ozone into it directly. I run all my RO waste water through the collection cup, which drains to a sewer line.
I set it up, and have never had to adjust anything on it. And it pulls out crud all the time.
I've run it with heavy bio-load, heavy coral load, and no load - and it's always pulling something out.