I have several in use. The only one that ever gave me any trouble was one that was getting heavy doses of Alk buffer too close to it. A quick vinegar bath, move where the doser discharges and it is good as new. I can't fault the one that I splattered salt water into the electrical plug in. That's just my own neglect...
As my older Dart/Snappers fail, I find it cheaper to switch to Jebao. FWIW, I've had significantly higher failure rates with a more popular US brand of DC pump.