i have a hammerhead main return pump (sump in the floor under the DT), a dart for the CL and an orca on my skimmer (dart with a needlewheel) for years with minimal issues. AO smith motors on the darts, baldor on the main. the main pump needed to have the seal replaced after three years, they sent me one under warranty, and it's been fine for years since. the other pumps have never had a problem. i occassionally (like once every year or two) take one off line and plug the input and let it sit with vinegar in it for an hour or so, that's been fine to clean off any buildup that occurs, it's pretty obvious when it needs it.
seals are easy to replace if you need to, and i've only needed to do it once with three pumps, several years of constant runtime.