The difference isn't really a big deal unless your driveway is 200 feet long! So the larger clearing width may only save you about 10 minutes versus making your snow blowing time much more comfortable and convenient.
Focus on the Features
You want to look at features such as power steering, heated hand grips, automatic chute control, and larger engines.
Power steering saves you from having to make wide turns in the middle of the street or horse it back-and-forth to change directions. It provides better handling, so more members of your family are capable of enjoying the benefits of a snow blower.
Heated Hand Grips
Heated hand grips are great for obvious reasons. No need to worry about frost-bitten fingers and your fingers won't be too stiff to operate the power steering triggers in sub-zero temperatures.
For those who feel restricted by wearing gloves, these are an effective way to maintain toasty digits in sub-zero temperatures.
Automatic Chute Control
Automatic chute controls allow you to control the direction you're blowing without stopping.
If you want a step up from a manual chute, there are options such as lever chutes, slide chutes, crank chutes, joystick chutes, and electric chutes.
So when you're shopping for a new snow blower, remember that it's the features that make them better than the models of yesteryear, and size is just an afterthought.