As far as I know there are two reasons that people got a buzz from cigarettes...
1) The carbon monoxide, which is essentially depriving your brain of oxygen
2) The possible interaction of the nicotine and the other MAOIs found in tobacco which can also be found in WTA liquids
I can get a slight "buzz" from using WTA liquid, but it's not the same buzz I got from the first cigarette (carbon monoxide) in the morning.
I've seen people talk about a buzz from straight nicotine, but I never got one.
Not sure what it feels like, but I guess it's probably a lot like downing a few cups of coffee really fast.
That would be a third kind of buzz I guess, sort of jittery.
I liked the calming buzz from the carbon monoxide oxygen deprivation myself.