I agree that these TJ's Vintage Ales improve with aging. I saved a bottle from 2010 and drank it in November. It definitely dried out, although because it seemed to have a very subtle hops profile, it wasn't anything special. However... these bombers sell for $5.99 (here in MA) and for a product from Unibroue (one of my favorite breweries - probably because I really like the yeast profile and high carbonation) it's a real bargain.
I would suspect that the "natural flavoring" is some sort of spice "extract", maybe intended to bump up the spice profile without using actual spices.
If you like Unibroue, and are looking for something that's nice enjoy with comfort food plopped in front of the tv on a cold evening, you can't really go wrong for the price. If you've got the space to tuck a few bottles away until next Fall, then I say go for it.
If you don't like Unibroue's other beers, then you'll probably not like this one.