Thanks for the responses so far. I think LouDiamond is probably right in that it's what you train and feel comfortable with. However, if I ever wanted to sell a shotgun with a PG, I imagine my prospective buyers would be fewer if I were trying to sell a PG stock as opposed to a "conventional" stock. If for no other reason than perception.
Also, from what I've read on this forum, it's more difficult to clean the Supernova with PG because you have to remove (or loosen) the PG stock to clean the trigger assembly. The Comfortech stock does not require this operation. Is this really a big issue as far as saving time or are most people simply pointing this out because the owner's manual didn't mention it?
For those reasons, I'm leaning toward purchasing the Comfortech stock on a Supernova Tactical as my first shotgun purchase.