I agree; opinions on this will vary wildly from person to person.
I am a complete n00b to e smoking; I just got my first REAL e cig, a Dura from VaporGuys (previous cigs included a disposable and a peewee).
In the first couple of days, I have been vaping like a fiend! I have made my own juice (essentially a glycerin tincture), and in my experimentation I have 'discovered' a couple of things.
It seems, to me at least, that nicotine adds the 'tickle', and glycerin adds the 'body' to the vapor, the throat/lung hit.
I have tried vaping straight glycerin, and I can definitely still feel it, but the tickly feeling isn't there.
I would venture to say that the thicker juices (the ones with more glycerin, less distilled water) would have a better hit, and the thinner juices (higher amount of distilled water) would be smoother.
In my (extremely limited) experience, it is the combination of those two elements that makes up the vast majority of what we call throat or lung hit. Everything else, heat, flavors, etcetera all seem to effect the experience as well, just not as severely.
But again, opinions will vary, and I am a noob. Take this entire post with a grain of salt.
Sean