rock on. My story is about the same. The biggest factor by far though, was optimizing the route to avoid lights. Even though it added a little more distance, I avoid major traffic areas.

Going from full suspension big knobbie tires to a road bike only shaved 5 min. or so. But the amount of getting my butt kicked decreased exponentially which resulted in being able to commute from 3 days a week max to 5 days no prob and still energy for weekend rides.