Question About Updated Os

[slicksterps1]

Hi Everyone,

I just came from the stealer and had my BMW 2001 4.4i os updated.(125.00) I just bought a used 6:9 nav screen on ebay, so I thought I would update os before I install the vew nav screen.( Yes, I have small nav screen now and MKIII is my current hardware)
Here is my old os vertion: SW 3-1/21
Here after os update: SW 3-1/31
I have three questions.
1)Was this the newest update for my year and modal X5?
2)Was it smart to install new os before I installed 6:9 nav screen.
3)what will change?

Please let me know.

THX