I agree with you. When I bought a pool pump for the first time I bought a metal one, and I bought a metal pump, but it broke down very quickly because there was corrosion started. After that, I went for a new
pool pump timer and was advised to buy a durable plastic one. And indeed, I have been using the pump for many years. By the way, a have a friend and he has a pool pump with a digital timer, it's easier than use a mechanical one. And there are a lot of setting options which you can choose and set as you want.