Just did this trek 2 weeks ago from Sosua using the mountain. It tool about 2 1/2 hours to Gran Jiminoa in a car rental - not sure how much time would be added if using public transit. It will be worth it Jarabacoa was really beautiful. Tip: Gran Jiminoa was an outstanding hotel and very affordable. If you do the horseback riding to the falls beware - they will say 1 1/2 hours - when we did it, it took almost 4 hours and I could not walk properly after for about 2 days (broken butt) lol.