Perusing this forum, I've seen a few posts that remind me of my "golden rules of beer aging." These apply to any rare beer more than two years old.
1.)If you have multiples in your cellar, "It's drinking fantastically now, and likely will continue to improve indefinitely."
2.)If you just drank the last one from your cellar: "It's either at its peak or just past it."
3.)If you don't have any of them in your cellar and don't care about acquiring any: "the last time I, or someone I know, tried this it was past its peak and it has probably gone downhill since."
4.)If you don't have any of them in your cellar and you desperately want to try some: "This beer is so far past its prime it's pretty much **** at this point."