A pipe that will sit in a stable way with the chamber up has a fine attribute. Straight pipes that will do this are a real convenience, but for the full benefit, bent pipes are good because their footprint can be so small. I have several sitters in my collection, among them two Peterson B11 bent brandy's, sometimes also sold as volcanos, that sit on about one square and a half inch. It's really nice at desk, or roaming around the house, to be able to park a lit pipe with assurance. My first pipe, bought in the seventies, is a bent pot sitter, probably a Chacom, a Tinder Box St. Ives. If you find a sitter you like, it will like you back.