John -- although I've never owned one, I've always thought they'd sound about the same.
Mike -- I think what we're seeing here is that for years the Ludwig Standard line was looked upon as "entry level" and these snare drums, just like their same-shell-as-the-vintage counterparts are just now beginning to be noticed... Kinda like the whole Club Date thing. When I was a kid, I avoided them like the plague. But now can't seem to find enough of them! As we're seeing, the Ludwig Standards are doing the same.
I recently picked up (off CL) and entry-level Taye set that came with a Ludwig Rockers snare drum. Much to my surprize when I put the SD on eBay it got quite a bit of attention/bids, and I got more out of it than I paid for the whole set (which I've since sold as well!) So, I don't really think it's a "shortage" of the more popular vintage stuff that beginning to drive this market a little, I think it's that people are just beginning to see that this kind of stuff is pretty good, too!
Bill