I did a 4 year old taste test against a fresh 120-minute. It was a different beer! It mellowed out into a rich barleywine-style beer. Here's a pic for comparison. http://i.imgur.com/IgWksJT.jpg
I also have a 4-year old bottle that I'd love to off-load as I don't much care for it. But only after OP's trade is satisfied.