Perhaps it's just because I was talking about it earlier tonight, not to mention a bit of drinking, but I think the hybrids vs heirlooms discussion is a lot like blended vs single malt whiskies -- the hybrids will give you a consistent crop with very good qualities that appeal to most people, but the heirlooms offer a lot of unique character, and might be better suited to a particular region.
And of course the ability to save the seeds each season is in itself a huge reason to grow heirlooms.
