There are 2 distinct bottlings of this. The labels will be identified by "Louisville" or "Frankfurt."
The Louisville bottling is from Stitzel Weller making it the most sought after and collectible. That was likely bottled by Diageo (pre 1998) prior to Buffalo Trace (BT) acquiring the brand.
After BT acquired the brand they labeled it with Frankfurt. There are 3 different iterations with the Frankfurt label and can be identified by the bottle shape and the wrapper covering the cork.
1) A square bottle with cut corners and black top wrapper stating "Bourbon Heritage Collection."
2) A square bottle with round corners and black top wrapper stating "Bourbon Heritage Collection."
3) A square bottle with round corners and yellow top wrapper. This wrapper does NOT state "Heritage collection" as BT dropped the heritage collection line.This is probably the last iteration of the Weller Centennial
There will likely be differences in taste due to year of distillation and to the nature of the small batches.