As a new vapor, I admit it was the phraseology "e-cig" that got my attention and something that I'd heard numerous times previously. If PV had been used it would not have made a "connection" for me.
As others have mentioned though, depending on the situation I am in, that will dictate the verbiage I will use. In a confrontational situation in public, I would most likely use PV or just vaporizer. In speaking with someone who is sincerely interested, especially a smoker, I would use "e-cig" and as fully as possible explain the benefits. And although I know it cannot be marketed as a "smoking cessation
device", I can and will happily tell people that I have not had an analog (or traditional cig to the uninitiated) since my first
vape.