I do 22 miles each way and it much easier on me and simply faster to ride my road bike with good 23mm tires then my MTB or hybrid. I do not carry any extra weight with an exception of spare tube and air tho. Also the gearing on the road bike are much nicer for hilly paved road, I can tune the gear with small increments getting the most comfortable ride. With my MTB that's not possible and I have to pick from only 3-4 (at most) gears on a road.