No smoke in your room or building. Directly after exhaling the aromatic vapor can be smelled by someone sitting nearby, but it doesn't travel far, and doesn't hang around for long. It certainly won't make anyone cough or experience any of the other common side effects of "secondary smoke". The smell doesn't get into anyone's clothes, car upholstery or furniture.
Vaporizing is much more efficient than smoking. You need fewer of your herb for an equally powerful effect. And because vapor doesn't irritate the lungs, you can keep it inside for longer, thus facilitating the absorption of more of its active components. Many vaporizers will only heat the herb as you inhale, so nothing goes "up in smoke" between puffs.
Vaporizing is much healthier than smoking. Not just for the throat and lungs but for the entire body. Tar, toxic gasses, radioactive particles and numerous free radicals are all absent or significantly reduced, depending on the quality of the vaporizer.
There is no fire involved. Long-haired people will no longer burn their hair trying to light their herbs. Other fire hazards are also eliminated.
Enjoy the natural aroma of the non-burnt plant. Though some herbs smell great when burnt (which is why unlit incense sticks smell so different from the smoke they produce), many people prefer the natural aroma of the plant itself.