My commute is almost 22km one way. With traffic (always bad), traffic lights (seemingly always red) and having to wait for the ferry to cross the river, I doubt I could cut much off of my 1:15 one way commute time no matter what kind of bike I was to ride. For example, I have basically the same overall commute time whether I'm fighting a headwind or enjoying a tailwind on part of my route, because any time I gain/lose as a result of the headwind/tailwind will be made up somewhere else on the commute. I think urban commuting where there is traffic and traffic lights to deal with will always be that way - your time is basically dictated by things beyond your control.