The two new releases in the Buffalo Trace Experimental Collection (BTEC) are both double wood. The first was distilled in 1993, aged for 8 years in a new barrel, transferred to another new barrel and aged for 8 more years. The second was distilled in 1997, also aged for 8 years in a new barrel, then transferred to another new barrel for four more years.
I tasted them yesterday. The one with the lesser time in the second barrel was better, good even. Woody, of course. The 16-year-old was too much. Bitter, acrid.
The original double-barrel was also distilled in 1993, but it was the BT2 (high rye) recipe. The new one is BT1 (low rye). That earlier one, like the new '97, was 8 years in one barrel, 4 in the other.
They'll be released in October. I don't know the suggested price, but they're typically $50+ for a 375 ml bottle. Pricey and also in very short supply.