DO NOT DO THIS IF YOU ARE IN THE US! I just did and while (thankfully) the appradio functions fine, Pandora is no longer supported.
The euro version of the software does not have Pandora support because pandora isn't available in europe.
Unless you do not use pandora do not update. You cannot downgrade back. There are a lot of under the hood changes to 2.5. The update process itself takes two microSD cards to do and updates the ECU, MPU, Bluetooth, and MCU. I doubt these settings will be compatible with older versions of the software.
Hopefully, if I'm lucky, the US version of 2.5 wil