This is the part that seems the most problematic to me. It's not just that you'll miss the warming effect of alcohol in a n/a version of a big beer. There's more to it, and you'll miss it even in a small beer. But it's hard to describe alcohol's impact on flavor, maybe because it's always there. If removing the alcohol can be done without otherwise impacting flavor, it would be interesting to do some side-by-side comparisons.
Anyone have a better handle on how alcohol interacts with the other flavors in beer? Does it accentuate particular flavors, or aromas even? Isn't the flavor of the alcohol itself a little bit sweet?