For me, my only answer is "it varies". When I smoked, sometimes I only wanted (or had time for) 3 or 4 drags. Because cigs are so expensive, I usually felt obligated to smoke the whole thing. With vaping, I often just take 3 or 4 puffs, or sometimes I vape for 10 minutes straight. I don't try to compare it to cigarettes any more. I am fortunate that I can vape at my workplace, but I still go to "the smoke spot" occasionally because I have friends that I only will see there.
I use a variable/regulated device (Darwin) and I find it great to be able to crank it up for more nic in the mornings (or stressed) and turn it down in the evenings. With a fixed-voltage device I just vaped for longer if I felt I wanted more nic. On fixed-voltage you can change atty/cartos for more or less vape and nic as well.
There is still something to be said for taking a break from whatever your work is, and getting away from it for a few minutes. Whether you are vaping, smoking, talking with friends, or daydreaming, your work goes better with breaks.