For my 2011 xdrive28, I looked into putting a "big brake kit" on, and with my research and talks with my local shop, the cost didnt outweigh the benefits I might achieve.
After that, I followed up with a brake bedding procedure, I think it helps with bite a bit. I didnt go crazy with the bedding procedure, since they aren't performance brakes per-se, or anything close to that.
Also, as others have posted....tires matter.