Lots of good points here. My point was really that Lakerider is already riding her mtb exclusively on the road. She could change its tires to city slicks (1.5") and use that as her hybrid bike if she wants a bike for errands and utility rides. The thinner, slick tires would be faster than what she has now, and quieter for riding on the road (no need for knobbies on the road!) But if she wants to be able to ride faster and longer on something a lot lighter than either a mtb or a hybrid, and if she doesn't have the money or the interest in two (new to her) bikes, then I'd go with the road bike!