Here is my .02 on sizing (hope this helps)
I have narrow feet.
I have worn a size 9.5 in EVERY Kobe from the 5 through the 10 EXCEPT for the Kobe 9 Elite HIGH. In the 9 Elite High, I wore a size 9. Every other 9 (EM low, Elite low) I needed 9.5.
I tried the XI in in a size 9, and way too tight. I did not find them to run long enough to warrant a half size down like the Elite 9 High did. Maaaaaybe a teeny bit long, but definitely not a complete half size.
Therefore, I also need a 9.5 in these, I don't recommend sizing down at all.