The 15 yr old has been buffalo trace juice for a while. The van winkles get the pick of the barrels and the rest goes to other BT products. Weller 12 is decent stuff but it aint pappy.
The 23 is the only one that is still all stitzel weller (unless you count the rye).
Calling weller twelve better or the same as pappy 15 is a stretch. That is like calling buffalo trace the same as george t stagg. Same mashbill yes, aged for different amount of time and in different place in the rickhouse.
A Bourbon getting lots of press that is readily available is 4 roses limited edition small batch. About 80 per bottle and really good stuff. The limited single barrel from 2012 was also excellent. Might be tougher to find but worth it.
Ps. Some places may get some more pappy this week so it might be worth ducking into your favorite spot. (Dont call, the answer is always no when you call)