You don’t really gain any functionality that you don’t already have with the DJTT mappings. What you do gain is all those buttons freed up on the VCI or the X1 to map other things to. To me seems it just makes using the labeled things on the X1 easier during mixes so I might be more inclined to use them when appropriate.
Yeh, I suppose you get better looping functionality and all 8 hotcues in 1 place. Also, easier access to individual effects on both decks at the same time.