West Maui Loop is the best road ride I've been on. The road is closed west of Kahakuloa Monday thru Friday for road construction. Stop in for Shaved Ice with Lorraine, she's a hoot! The Road to Hana is just hammered with cars so I'd pass on it. Quite unpleasant to drive there as well. There are very few cars on the West Maui Loop. Haleakala is something you only have to do once. Climb for 36 miles 10023'. You don't coast at all on the way up. It's like riding an exercise bike all day. Do it, you'll never forget it. Good bike shops in Lahaina and Paia.
Plus one for Lorraine's. Julia's Banana Bread is indeed among the best I've had, and worth the hype (remember to pet the dog!). Lorraine (follow the coloured curbs, just south of Julia's) is a real gem. She made us on-the-spot banana bread ice-cream sandwiches, and gave us a real nice tour of her little banana farm. Maybe one of the sweetest moments I've had in my trips to Maui.