I wasn't aware that there was a new 12 yo expression of the Talisker DE (are you sure it stated 12 years old?). I've tried the 1986 version which carries no age statement and agree that the Amaroso finish both lessens the attack and alters the classic LONG finish of the Talisker 10. Personally I'd agree that it's a less distinctive product, but I still enjoy it from time to time.
The multi year Distillers' Edition releases was a marketing ploy by United Distillers to counterbalance other distilleries' marketing of sherry finishing. Not to be outdone, they took their self proclaimed "Classic Malts" (an earlier markeing ploy that proved to be very successful) and added various types of sherry finish.
I've tried the Talisker, Cragganmore, Lagavulin, but not the Oban, Dalwhinnie nor Glenkinchie. These were the six distilleries involved in the project.
The lighter malts (Dalwhinnie and Glenkinchie) apparently improve with the treatment. Surprizingly, many also believe the Lagavulin was actually improved with the treatment, especially the 1979 release which garners a very high "score" especially from Michael Jackson.
Consider the Talisker DE as a light sunday morning malt, to be folllowed by the 10 or 18 in the evening! Enjoy!