There has been much debate amongst whisky enthusiasts concerning the relative merits of the older Port Wood editions and the newer Quinta Ruban release. Therefore, I'd strongly advise, if at all possible, personal and direct comparative evaluation of the two.
Some aspects are evident right off the bat, though. The Quinta Ruban, as already pointed out, has dispensed with the chill-filtering that 'plagued' the previous Port Wood. And its bottling strength is 3%ABV higher (46% versus 43%). These factors, one would think, couldn't help but lead to an improved product. On a slightly negative note, the retail cost of the newer version has increased, vis-a-vis that of the older, in most markets.
For me, taste-wise, the differences appear even more dramatic. The older Port Wood seemed to display an effortless drinking quality born of a silky texture and decidedly winey sweetness, particularly on the finish - I've been reminded of Turkish delight. It also possessed, particularly in its earliest incarnations, an overall smoothness that clearly pointed to the incorporation of some whiskies aged well beyond the minimum stated age (at least 12 years in ex-Bourbon wood followed by fa urther 'finishing' in Port casks). In contrast, the Quinta Ruban comes across in a more robust, assertive fashion. And the sweetness is further counterpointed by additional spicy notes derived from those 'higher quality' Port casks now being utilized. For those who loved the older edition, the newer one might - at first acquaintance - seem to be a 'rougher ride' on the palate. It certainly has spirit! Personally, I have to wonder if the average maturity of the whiskies now blended into the product may have diminished a little. Who knows?
Do the innate characteristics of the Glenmorangie distillate (especially those lovely spicy overtones) percolate through more clearly in the newer Quinta Ruban? Probably. Is it a more challenging whisky? I'd have to say, "Yes." Do I still miss the older Port Wood edition? Definitely.