This update is recommended for all Mac Pro (Late 2013) systems. It includes all updates from OS X Mavericks 10.9.1 plus system-specific enhancements and fixes to improve the stability and compatibility of your Mac.
What's new in OS X Mavericks 10.9.1 Update for Mac Pro (Late 2013)
This update includes the following fixes:
Improved support for Gmail in OS X Mail, and fixes for users with custom Gmail settings
Improves the reliability of Smart Mailboxes and search in Mail
Fixes an issue that prevented contact groups from working properly in Mail
Resolves an issue that prevented VoiceOver from speaking sentences that contain emoji
Updates Shared Links periodically when open in the Safari Sidebar
I've tried using 10.9.2.. it's an upgrade from 10.9.1
with a few differences.. but those differences might
be what make you RETURN to 10.9.1 I useSL for
as well as ML.. if you have 10.9.1, and it's Working
Keep it.. Remember years back when someone said
you've got a TEN-9 radio, and what that meant!
BTW.. I only use Gmail on the web ONLY!