I thought I could finally use my expertise for something good!! Here is the way I see it.
Genie is a mixed bag when it comes to quality. You can have a unit that lasts 20+ years and then one that lasts less than a year. Quality is all over the place with this company. I guess you can say that about any manufacturer, but it seems more bad then good with these guys. Customer service also seems to be a negative experience. The good news is that the unit is assembled in the USA, but that does not mean that all parts are manufactured here. Also, just like any other brand, Genie has low end and high end. I would stay away from their low end at all costs. Their low end is really low end.
Chain vs. Belt vs. Screw
Chain's Pro's: Very long life, Affordable
Chain's Con's: Not very quiet and requires maintenance
Belt Pro's: Very Quiet, Almost Maintenance Free, Most have lifetime warranties
Belt Con's: A little pricier
Screw Pro's: Very affordable, quiet (At the beginning)
Screw Con's: Short lifespan, They can get loud over time if screw ever gets out of round, Requires maintenance
I am not a big fan of the screw drive mainly due to the stuff listed above, but also due to the screw driver coupler that will fail. It isn't the easiest thing to change for a novice.
What you can expect in terms of maintenance required and parts that will fail:
No matter you choose chain or belt, they both have plastic gears and cheap sprockets. When one breaks, you should change out the entire gear sprocket assembly kit. They aren't always the easiest to change depending on the brand, make, and model. The good news is that once these are changed out, you basically have a perfectly working unit that lasts for a long time.
In terms of maintenance, whether you have a belt or a chain, you should always lubricate the unit. I would suggest a couple of times a year if you can remember.
Genie vs. Liftmaster....
I love this debate. If there was one thing that would keep me away from the Genie product is the sensors. They have long brackets that attach to the wall and not the track. These brackets are very flimsy and have a tendency to move around a lot and knocking sensors out of alignment. Liftmaster has sensors with special brackets that attach directly to the track and are a lot harder to knock out of alignment.
Another issue with the Genie product is it is made of mostly plastic. They have tendency to dry rot. When I say plastic, I mean the trolly, the unit assembly, just about everything, whereas the LIftmaster units are mostly metal.
I always suggest sticking with the reliable and proven Liftmaster brand. Also, if you can wait a month or so, LIftmaster is about to release all new models which will have iphone controlled functionality included in their Estate series motors. If you look a the following website, I would suggest any of these.
3585 - 3/4 Motor
3850 - 3/4 Motor with Battery Backup
3280 - Standard 1/2 HP Belt Drive Motor
These guys also have a pretty decent blog for general information: