iOS6 UDID - What advantages does identifierForVendor have over identifierForAdvertising?

Question

Apple is changing their privacy settings for iOS6 and deprecating device UUIDs (UDIDs). According to a WWDC presentation and the docs there are two replacements for the UDI

Answer 1

User can change identifierForAdvertising any time in Settings, identifierForVendor changes after reinstall app, if no more apps on device from this vendor.

Here is alternative and the best solution for get or persistent, cross-install Device Identifier:

description: https://blog.onliquid.com/persistent-device-unique-identifier-ios-keychain/

code: https://gist.github.com/miguelcma/e8f291e54b025815ca46