The problem is any potential productivity benefits are usually shut down at the employer level - I've never seen an employer (specifically office environment) that allows vaping in the workplace. My employer requires people to clock out for a smoke break and go outside anyway, so to get the next hit people have to go break momentum away from their desk for a while - and that'd probably be quite frequently too; from my somewhat brief stint(s) of trying to adopt vaping over combustion, I'd find myself puffing on it far more frequently than I'd go for a smoke (which at work is about 1 every 1-2 hours or so~)