If you're "repeating the works of the greats" in grad school, you're doing it wrong. That's what undergrad is for, and maybe a masters, but getting a PhD is supposed to be all about producing something new. By the end you should be <i>the</i> world expert in your (admittedly narrow) area, and have produced published scientific results that were previously not known to the field.<p>Overall though, they're two totally different things, and if you don't know which of the two is more appealing to you, you don't have a very good idea of what you want to do. Do you want to advance the current state of scientific knowledge? Or do you want to produce products and services that people will find useful? The two occasionally overlap, but in general they're fairly different occupations.