Biggest difference: Comcast is Cable service and QWest is DSL service.
Next, however is QWest will soon be renamed as Century Link has made a offer and is buying QWest.
I setup my parents with QWest down in Albert Lea in January and works great. They have the slowest DSL speed due to distance from switch station and yet very quick, no problems. When bundled w/Phone service in best price package it still cost me almost $600 for 1st year with setup charges, etc.
Well worth it when they can watch video’s of my Grandson (Their 1st Great Grandchild) on facebook Video’s to see what he’s up to and how he does funny things.