DX is more banana and less creamy than regular banana cream. (what i read on reviews; also this 
).
Both Banana Cream and DX Banana Cream have Butyric Acid, the only real difference is the exclusion of Acetoin in DX Banana Cream. I don’t mind that part much. What makes the real difference here is the Isoamyl Acetate is used slightly higher in the DX version, making for an increased Banana flavor, slightly less creamy. I prefer this one to be honest, it is slightly more concentrated and very easy to use. I have always enjoyed the flavor.
I bought BC DX recently after reading good reviews, but i can’t compare it with Reg BC since i never SFT’ed that one; i tried DX at 6% solo and it had no unpleasant notes to me (but i’m not very sensitive on BA); haven’t tried it in a recipe yet.