Like I said, you really only need a handful of bowl shapes. I lied when I said only Burgundy and Bordeaux stems since I also have white wine stems, but I use those for sweet wines. Confused?
Well to a certain extent, that's what manufacturers are hoping to capitalize on, your confusion. There is plenty of truth to the notion that different wines shows differently in various shaped glasses, the question is, do you care and are you interested in spending the time to find out?
For most people, that's an easy question to answer. For those of us who answered no, our needs are amply met by a pair of glasses with a nice graceful arc to the bowls, allowing for sufficient surface area to release aromas and ample space to capture them.