Does the limestone make it better?
Absolutely!
If you have Netflix, watch a documentary called Bourbontucky. Fred Noe, son of Booker Noe and great grandson of Jim Beam tells about people always wanting him to taster their “bourbon”. He says, that is a fine tasting whiskey, but it ain’t bourbon. LOL.
There are some non-KY (no Clarke, not that KY) bourbons that are made where the water is filtered in limestone. One that I recall is Widow Jane which is made in NY but the water in that part of NY is filtered in nature by limestone.