The main variable in garage door opener options is the type of 'drive' the opener has, or what mechanics work to open the door. Basically, there are three main types. Chain drives, like a bicycle chain, is rather clunky and noisy, but sturdy and reliable. Screw drives operation through use of a twisted spring, and operates metal-on-metal, meaning that it also tends to get noisier as time goes on and the lubricant wears off.
Belt drives, on the other hand, is a similar mechanical process of the chain drive, only using a rubber belt instead of the chain, which greatly reduces the decibels that must be endured as the door opens. It's still a rather large motor movinga rather large object, but it's much quieter than the older technologies.
Of course, there's a price tag that goes along with switching to belt drives, not including the price of the garage door services.
Some garage door openers come with sophisticated keypads, some just with openers. Again, it's a question of how much you're willing to shell out for it.
Of course, there are endless choices when it comes to special features on garage door openers, which we may touch upon in later posts.