I'm on 19 seasons of coastal sailing with a Raymarine ST-4000.
As they are pretty fragile, and our boat at 38' and 16,000 disp., on the heavy side, I didn't expect it to last this long. I
t's had a few belts replaced, a wheel or two broken off that I repaired, but that's about it.
It has steered most of our miles over 19 seasons, I would bet.
I didn't and still don't expect it to work in all conditions, especially down wind when the wheel needs constant tending.
I don't beat it up, when it's overwhelmed, we find a better sail trim or configuration or change course if we can.
I've realized what wheel pilot likes - the crew (and I) likes as well, so it's a win-win to makes these adjustments.
It's taught me new tricks on sail trim that can keep it happy. It requires changing the rudder gain settings and speed in different conditions. Good gizmo, I'll replace with the newer version,... if it ever dies.