I feel like I can tell a difference in shift speeds when in comfort compared to sport/+ modes. More specifically I feel the kick like a DCT does when flappy paddling it myself, gas floored, but shifting around 5K instead of 7K. The transmission is amazing in my opinion and very comparable to a DCT in shift speeds.
In comfort and eco pro it shifts very smooth and don't notice when it shifts. In sport/+ it keeps the rpms at a minimum of 1500 so you're always in boost (except when stopped of course) so power is always there. To me it controls the transmission how I would if in a manual, 2-3k when doing spirited driving through corners and 1500 when cruising. I will warn that driving in sport mode constantly will make your mpg drop. BMW won't tell you this but your foot actually gets heavier when you switch to sport/+ modes
I've been averaging about 19ish mpg staying in sport mode constantly. When in comfort and eco pro I get around 22-23 for my daily commute.