[size=12]I can't really speak from experience, since when I cook with cast iron it's usually Wal-Mart Lodge size 8 or cheap Taiwanese skillets of various sizes, and I'm usually just cooking for two people. I have an electric glass-top GE, and have very little experience with gas ranges of any kind, though I might add that none of it was pleasant. I collect Griswold all across the board, but refuse to use it to cook with for fear of warping or cracking mishaps. I know a lot of people on this board love using antique iron for meals, but I don't go that way myself.
My point is, I would think that, if you're talking about antique, collectable size 12, 13, 14, or 20 skillets, you might want to think it through before you toss an expensive and large chunk of vintage iron across two or more burners of a modern day range top oven. A lot of the warped big skillets that I've seen out there have a medium-sized discolored circular spot around the warped area, which makes me think that they got that way because somebody was trying to use, for instance, a size 12 skillet on a burner designed for a size 8, and they heated the center too fast for the sides again and again, ad infinatum. You mentioned something about a glass cook top, and I've heard that those things aren't cheap to replace, either. Not to mention the fact that the heavier the skillet, the more likely that someone will drop it, especially if it's full of food and burning hot to the touch.
So, you might just be better off using multiple smaller skillets, in the end. Just my two cents.[/size]