I'm afraid the sad truth of the matter is that no electronic cigarette is right for everyone.
Each model has it's own pluses and minuses in relation to what each person is looking for, wants, and needs from the vaping experience. Some may want more flavor, some may want more throat hit, some may want more battery life, some may want something that doesn't look anything like a cigarette, some may want something that looks exactly like a cigarette, some may enjoy fussing with them, some want one that takes as little fussing with as possible, some may want to press a button to activate the battery thus giving them total control, some may not ever want to do that, some may want a very light model that can hang from the mouth, some may not care about that.
The bottom line is, if you buy a bunch in bulk of the same kind, some will like it but you can count on many that will want something different eventually. I would actually suggest getting a few different kinds and then you have a group of people that can exchange and borrow from each other to find out what they are really looking for.
I sure wish I knew a group where I could do that.