With an older wine like this, a lot of factors go into what it'll taste like with significant age. Crazy as it sounds, you can take a case (12 bottles), of quality age-worthy wine, split them up in different storage situations, come back in 20 years, taste them all, and have 12 different experiences. You might think one bottle is absolutely terrible and subsequently dump it, and the other bottle might be positively sublime.
Assuming the bottle was well cared for, something called bottle variation can have an adverse affect on what's inside, amplified over time. I think of "bottle variation" as kind of VooDoo land. I've had wines from the same case, side by side, and one tastes different. With time, the differences grow.
While I haven't had this wine, it's reputable wine from a blockbuster vintage. My guess, if it's in good shape, it'll be smooth, and won't have much fruit to speak of on the nose, but will have a lot of complexity. No need to decant this. Get some appreciative loved ones to share it with, let 'er rip, and report back with your impressions.
Don't forget to let it sit upright for a few days to let any sediment collect at the bottom, and pour slowly and gently to keep it there.