I have been a fan of shift kits for automatic transmissions since I have been driving. In fact, my former '66 Dodge Dart GT V-8 had a shift kit even before I started driving it (my brother put one in after he tuned the engine and before I got my driver's license).
I think a quick and firm shifting transmission is so much better than a soft-shifting one, especially for a Mopar with a high-performance engine.
I like shift kits so much that even my '69 Cadillac Fleetwood Brougham has one. Much better to drive; with the stock transmission, it seemed to take forever to complete a shift, especially 2nd to 3rd.
I also own a '76 Cadillac Fleetwood Seventy-Five Limousine and while it doesn't have a shift kit I have considered one even for that car! What do you think... should my limo have a shift kit? Not the hard, tire-chirp type of shift, just firm instead of mushy.