(BTW: The original (non-machine specific) OS X 10.9.1 download page (DL1707) was later named for 2013 Mac Pros and the generic 10.9.1 D/L page changed to DL1715. Not sure why they didn't just use the later DL1715 for the Dec 19th posted Mac Pro 10.9.1 updater.)
Here's the doc About the OS X 10.9.1 Update. (See below for Apple docs on security fixes in 10.9.1, Safari 7.0.1 and 6.1.1.) I updated the (rarely used) 2012 mac Mini (after a backup) without any immediate issues. (Although after the update/reboot I had a repeat of the Disk Utility boot disc verify not showing a message it completed, but a shutdown/cold start resolved that.) Build number after 10.9.1 update is 13B42.
You can check for OS X 10.9.1 feedback in Apple's OS X Mavericks forum and the specific Desktop or Notebook forum for your mac model. (Not all problem posts are common but 10.9.0 had more than its share IMO, even for a dot zero release. Worse cases were those that lost data on external drives.) Also remember Browser updates may cause problems with 3rd party plugins/addons. If you have a problem, disable/remove them and/or check for any updates to them.
NuGuard KXs Screen Armor for iPhone, iPad, iPad mini and iPad Air
Article on Loophole in Safari v6.0.5 (Reportedly fixed in Safari 6.1 and later)
Review of NuVo Wireless Audio System
Updated Apple Support/How-To/Troubleshooting Articles:
- Using System Info to ID USB ports on your Mac
- Some files may be converted when opened in QuickTime Player in Mavericks
- Fix for unable to create netowrk user in OS X Server (Mavericks) after upgrade
- iPhone: Hardware troubleshooting
- Guide to Cleaning Apple products