Chuck Cowdery has mentioned elsewhere that within the last 10 years, Brown Forman has tweaked the recipe by adding bourbon. Apparently Southern Comfort, for many decades at any rate, was a combination of GNS and a fruit concentrate.
Sometime in the last decade, bourbon was added and real fruit.
A friend of mine, Les Piller, had a bottle of Southern Comfort in his bar for many years (he thought 7 or 8) and lent it to me to compare to a current bottling.
The current one has a legend stating that the original recipe of M.W. Heron is followed; the older bottle (both 35% ABV) does not contain that statement.
The older bottle has a "95" embossed in the base and clearly was made and sold around that time.
The current one was bought a few weeks ago in Ontario.
In my view, there is no question they are different and no question the current one is better.
The oldie has a similar (virtually identical) smell but the taste is not the same. The current one has a deeper, richer taste. Also, it has a woody or gritty middle that is absent in the oldie - that is the bourbon, probably added in about a 20% ratio.
The oldie has a quick, light finish: it tastes like vodka married to the Southern Comfort fruit taste. The current one has a longer, more complex finish.
Kudos to Brown Forman for restoring the drink to tradition. Whether or not it is truly the original, it tastes more authentic (to me anyway) than the former version.
It is excellent on its own and makes a great U.S.-style Rusty Nail (50/50 Comfort and any good Bourbon).
Gary