I have had this whole line in the last year:
"I could choose from: 1985, 1988, 1991, 1994, or 1998."
I really do like the 1985 the best, but each of the vintages are very different. So it kind of depends on what you are looking for. The 85 is more of a rich contemplative dram (more sherry cask influence). Where the 1994 and 1998 are more of a light, before dinner dram. They pretty much pick the vintages to express different things. They are not trying to just make the same thing over and over in younger and older formats.
One thing to do is, check the label. They give 'characteristics'.. You can check out the label notes on their website:http://www.theglenrothes.com/
See if you like the notes and go for it.