I would guess pretty close to the same, puff for puff. Maybe a tiny bit more. For one thing, I don't work, so I went out for a smoke as often as I wanted. And I smoked in my car. It seems to everyone around me that I vape more, but you don't have to puff-puff-puff an e-cig like an analog. You're not wasting anything letting it set.
I always have my e-cig with me. I can take a hit or two then finish the dishes, and take another hit. I very rarely sit and do 10 hits in a row.
That said, I smoked 1.5 PAD of Camel wides, or 2 Marlboro blacks. I'd have to cut back on my sleeping to puff more than that, lol. I go through about 1.5 mls to 3 mls of 6mg a day. Not sure how that compares.