An opener is sized to a door, not to a catalog page. Two households with the same garage can need very different units. Start with the door in front of you, then look at how the people in the house use it.
Weigh the door
Note the door material, its thickness, and whether it is insulated. Heavy insulated steel doors, tall doors, and wide doors put more load on the opener. Look at the door's spring setup and the track. A door that is hard to lift by hand is a poor match for a light-duty unit. Ask the installer to confirm the door weight and the lift type in writing so the unit is rated for the actual door, not a guess.
Count the real traffic
Write down who opens the door, how often, and at what hours. A household that uses the garage as its main entrance will open the door many times a day. A garage used for storage may open it only a few times a week. Ask whether anyone needs remote, keypad, or phone access, and how many remotes you will need. Each access method adds a little complexity, so decide which ones matter before the install.
Choose the drive for the room above or beside it
Drive type affects noise and upkeep. Belt drives run quieter, which matters when a bedroom or office sits above or beside the garage. Chain drives are common and sturdy, though they are louder. Screw drives sit between the two. Ask the installer what each option sounds like in a room like yours and what the lubrication or tension routine is.
Settle the backup power
If the household needs to leave the house during a power outage, ask about a battery backup. Confirm where the battery sits, how long it is expected to run the door in a typical outage, and how the door behaves once the battery is depleted. Ask how the manual release works and where the release cord hangs.
Check the safety reversal
Every opener should reverse when it meets an obstacle, and the installer should test the reversal and the sensor alignment at the end of the install. Ask them to show you the test and to write the force settings down.
The opener page on this site gives typical service life and the points to plan for. Use it to set a planning date from the install year, not from the day the unit starts to feel slow.