There are an awful lot of variables in these questions... I'd say the quality of upkeep, coupled with the actual use (ie hours on everything) and the environment in which the boat lived would have a great deal to do with how well it might "age".
This would not be regardless of original quality, but poor upkeep on a quality boat will degrade it faster, obviously.
Then there's the "cachet" of owning an Oyster over a "garden variety" Jeanneau (no offence to Jeanneaus, btw)
The older boat would not enjoy some of the newer features on recent designs, some of which are in fact improvements. But at 50ish feet you're going to have lots of space anyhow....
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)