I use the OM4 and love it. I got mine used and it's been running 2 years now on my system. The first year it ran 24/7. But for the last year I've been turning it off at night from 1 hr after lights out until 1 hr before the lights come back on. I still have a 3400gph pump in the sump running thru a SCWD and out thru spray bars behind my rock wall. The OM4 has 3 Revolution' heads by OM which do by far the best job of creating random flow in the tank of anything I have seen so far. And in 2 years I haven't touched the CL system. As for expensive pumps, I have a Reeflo 2400gph ($225) on the CL and a cheap Jebao 3400gph ($110) in my sump. The Reeflo did spring a leak and Reeflo supplied parts to fix it for free. However, the Jebao has run 24/7 for over 2 years, so I bought a spare just in case. And if the Reeflo craps out, I'm replacing it with the Jebao pond pump and buying another as a backup.
As for bulkheads leaking... in 7+ years I have never had a single bulkhead leak. Maybe if you try a little routine maintenance you wouldn't have leaks either.