I recently opened a newer bottle of Ardbeg 10 and found it did not live up to my previous tasting. It seemed much maltier and younger than I remembered without as much of the wonderful mouth-feel or apple notes. It still has great smoke and peat though, and I would guess I'd grade this bottle out at about an 89.
Doing some research on Ardbeg, I find that the distillery was moth-balled before Glenmorangie bought it in 1997, and that from 1997 until about 2008, Ardbeg 10 was released using old stocks of whisky. The result was that much of this whisky was actually much older than 10 years and some of these bottles are extraordinary. Luckily, I have an extra bottle from the time I bought my purchase for the first review. The bottle code begins with L8, meaning it was bottled in 2008 and likely one of the last bottlings of the old stock of whisky. The newer bottle I have begins with L9 and is likely one of the first bottlings of the newly available 10-year-old whisky. It will be interesting to see how Ardbeg 10 continues to evolve in the future.