With our regular car in the shop after catching on fire Saturday night, we're using a loaner - a manual transmission turbo-diesel truck. After driving to work today, I understand why 98% of the cars on island have automatic transmissions, and I only had the minor obstacle of Zion Hill to traverse, not the 1000 ft climb to the house from Road Town.
As I've mentioned before, the grade here is steep, and if circumstances arise while you're going uphill that cause you to slow down, you'll need to downshift. Downshifting in an automatic is not a problem - just pop the gear lever down a notch. Downshifting with a clutch on a hill is no fun, since it's accompanied by a sensation that, should you fail to shift fast enough, gravity will win.
On the other hand, the engine braking offered in a manual transmission car sure is nice for the downhill parts of your trip.