Although the vapor is usually fruit flavored and smells better than a ashtray like cigarettes do, the vape users should do their thing with the cig smokers. You could announce that right up front however you would like. It's your store, your rules.
While it may ‘smell better’. It is full of chemicals. Some of them actually make me sick. (smoke from burning tobacco or other plants does not) Same with some air ‘fresheners’, candles etc. Clean and fresh has no smell!