So who is right which is better? At the end of the day it is a matter of preference, not totally unlike the way you like your hamburger cooked. The difference is that in a dark roast you are going to taste more of the roast flavors. A light roast maintains more of the distinct flavors of the individual coffee and is usually brighter. Many do not realize that a cup of light roast coffee will typically have more caffeine than a darker roast. This is due in part to dark roasts cooking off some caffeine and also because light roasted coffee beans are denser/smaller than dark roasted ones, so when you scoop your coffee beans you are actually grabbing more coffee and thus more caffeine.
So what is better, the rich caramel flavors of a dark roast or the bright flavors of light roasts? It is really up to you.
I enjoy roasting light and dark roasts and giving out samples in an effort to broaden the horizons of coffee consumers. We roast to your liking , because at the end of the day, or more likely at the beginning of the day, you are the one drinking your coffee.