It doesn't install w/ amber, you have to manually install it from the link provided. To check for updates go to setting, phone updates and check for updates, GDR2 should start downloading if already not updated. You can check the version # in settings, phone info, the firmware version for GDR2 should start w/ 30....
Also after the update, download an app called SysApp Pusher and check for updates for all the Lumia System apps.
I downloaded and installed GDR2 with Amber last night by going to "Settings > system > phone update > Check for Updates" and wasn't given a choice of installing Amber seperately. (You need at least 1 GB of free space, I would say, dispite a notice in the process that you need 200 MB. I kept uninstalling groups of individual Apps, trying again and getting error message "801882e8" then removing more Apps and trying again. Third time worked. About 2 hours total time. )
When completed, "Storage Check" was installed as part of the process. It is found at "Settings > system > storage check" After installing was done, I still had 7.2 GB of OTHER! Using Storage Check it is now 4.9 GB.
I've never found "SysApp Pusher" in the WP8 Store?
UPDATE August 25, 2013 3:23 PM CST:
I just received an App Update to Storage Check. It was indicated with a release date of 08/23/2013. I installed the update before checking what the date was on the original one. I don't see any differences. The Maps still don't indicate an option to move the Maps to the Storage Card, only to "Remove maps from your phone and download new ones."
- Kevin on Verizon Lumia 822