Our Wayne-Dalton iDrive quit -- although the motor was supposed to have a lifetime warranty, they are no longer made and no parts available.
I read the reviews of the German-made* Sommer Synoris 550 opener and decided to buy one. Lowe's and HD both sell them for the same price ($228), but only on line: not in the stores. Adding the wireless keypad gets the total price into the free-shipping category. (Amazon also sells them, but there is no free shipping option.)
The design is very simple: a 24V DC motor with a sprocket travels along a fixed chain inside a metal C-channel. A metal arm connects the door to a carriage containing that motor. It is very quiet but significantly slower than the iDrive (which was claimed to be much faster than other drives).
Cons: a) the wall station is not wireless as the iDrive's was, so there is additional wiring to run; b) the iDrive had a delayed-closing feature, so that I could press the button and walk out through the still-open door, which would then close behind me; c) no staples were included, so I had to make a special trip to the store to buy some to staple the wiring in place.
*It really does seem to have been made in Germany, not in China with a German company's name on it. Those poor German workers! Fancy being paid even less than Chinese workers so that they can keep their jobs!Perce