I feeled burned everytime I see a leaking cork or drink a corked bottle of good wine. I just picked up a bottle of 2004 Puligny-Montrachet 1er cru from a good producer, while on a trip a week ago. After driving all day and getting to the hotel, I saw sticky wine dripping down the bottle. The cork was leaking. 67 Euros spent, (that's like $500 US Dollars given the current exchange rate (not really but it seems that way)) and the wine shop was hundreds of miles away, and I hadn't noticed the leak until later. Synthetics/screw tops may leak when they are under extreme pressure, but corks leak for no good reason other than imperfection or natural variations in the wood grain. As for ageability, I have never seen proof one way or the other. There are lots of theories, oxygen permeabilty rates, a few anecdotal stories, that sort of thing, but know one truely knows. Proof won't come until someone bottles some Bordeaux and/or some other ageable wines using both synthetics and cork, stores them in identical environments, and periodically tastes the two, side by side, over the course of decades. Now someone just needs to step up to the plate and get this experiment started. I volunteer to taste.