[CarT01]

An I-Stufe Update makes the CAS a little bit safer, its not so easy to clone keys, make new keys or read ISN and write ISN over OBD...

[milkyway]

Hello!

The design from the board computer is different. Since 14-07-50x it looks smoother and in my eyes better. The night design of the navi screen is better and you have a new menu if you press the iDrive during a navi session. The signs on the left side are also different.

CU Oliver

[osd]

There are often minor improvements which don't take effect on every car. Sometimes you don't even notice any kind of changes.
As far as I know there are no descriptions regarding improvements and changes.

Never touch a running system...
If everything is working fine on your car there is no need for updating any module. Except for official improvements announced by BMW.

Well, it is not exaclty true. I can give you for example N52/N52N/KP engine, where there are often problems with solenoid valves, new software have procedure which flush them with oil, so there is no oil dust keeps inside. So it prevents failure. You won't feel it but it works.

[abuqutaita]

If you have a battery charger/power supply, and about 1-2 hours to kill, ISTA/P is a pretty safe way to just keep your car on the latest and greatest, even if you don't know what's changing in every update. It's certainly safer than attempting to flash your ECUs using E-sys. In fact, I've used ISTA/P in the past to recover from bad flashes attempted via E-sys.