CG = Center of gravity, pipes like a Calabash are on the extreme end of bent, and hang very comfortably in your mouth. Straight pipes take a lot of clenching of the teeth to hold on to.

I usually get between 45 minutes to an hour out of a bowl, but that can vary dramatically according to pipe bowl size, what you're smoking, and your pace. If you're looking for taste similar to cigars, I would obviously stay away from aromatics, and try some good English blends, Virginias, and Balkans.