I have one of the wall mounted units; specifically the Liftmaster 8500. I did need it, because there is no overhead clearance in my garage. Prior to that I had a screw drive unit mounted vertically on the wall (but that’s a thread for the pit).
It’s fine. Much quieter than the old screwdrive unit. It has a battery, but I’ve never had need to use it. I guess I could unplug the opener and try it just to see what happens. It is connects to wifi with the MyQ app.
Connecting to wifi was a bit clunky, but then it worked. Mostly because you connect your phone to the opener, but then the phone is too smart by half, can tell it doesn’t have internet, and so disconnects from the opener and back to the normal wifi, or mobile. Enough messing with it got it connected, but I’m very good with technology, and it was a pain. My guess is all of the Liftmaster models will be similar.
Once it connected to wifi, I’ve never had an issue, or had to reconnect it.
The MyQ app is fine. I haven’t bothered to put an outdoor panel to open the door, because I just use my phone. Open the app, it shows if the door is open or closed, then press the button to change state.
The wall mount comes with a remote controlled LED light. That’s nice, because I could put the light in a convenient place in the garage, and then the opener turns it on and off as needed. That light is an option on other controllers, but comes with the 8500.
The 8500 also comes with a dead bolt that locks the door closed. I’m not sure if that is needed either, as I couldn’t lift the door without releasing it from the motor anyway, but it’s there, and it works.
The 8500 also comes with the nice wall controller that has the time and temperature on it, plus a motion sensor to turn the LED light on. That is nicer than a simple button.
Bottom line, if you really want quiet, the wall mount is even quieter than a modern chain drive, but probably not by enough to matter. Otherwise, it is a nice compact install. It is big, just big in a place that is out of the way.
I’m not recommending against it, but I can’t think of a good reason to spend extra for one over a chain drive. I think the wall mount is maintenance free, but I don’t know if you have to do anything to a chain. A screw drive, on the other hand…
One more thing. Using the new openers with the builtin garage door controller on an older car requires a special box. I got it to use with my old truck, and it works perfectly. It only works with in-car Homelink controllers, not with old standalone remotes.