I own two good road bikes and love them.
I also own a Treck Hybrid 7700. It is a great bike for limestone trails with 700x38 tires.
I fitted that hybrid with 700x25 and did some road biking. Was not much slower on the flats than a good road bike. Of course in the hills the weight will kill you.
Comfort? I am equally comfortable on the Hybrid as I am on the Treck Madone. Going on the drops takes a little more practice as do using the aerobars.