I have been told by a plant manager of a local soft drink company that using glass bottles actually changes the flavor vs. cans or plastic bottles. Something I always thought I perceived but wondered if it was in my head. I always preferred glass bottles over the alternates and was extremely disappointed when this bottler moved to cans and plastic as it was one of the last glass hold outs still around.
This was years ago but it has to do with the amount and/or method of carbonation. This makes sense as although the bubbles make soft drinks fun and add to the experience, CO2 doesn't actually taste good.