When I bought my first servo, I checked out every brand I could, and the one with the best features was the Reliable Sew-Quiet 3000. I have two of those and then bought a Sew Quiet 4000. I have not had one problem of any kind with those three motors. If I was going to buy another one, it would be a Sew-Quiet 5000.
No one lives forever, the trick is creating something that will.