Is it safe?

The 10.7.3 update is recommended for all OS X Lion users and includes general operating system fixes that improve the stability, compatibility, and security of your Mac including fixes that:

• Add Catalan, Croatian, Greek, Hebrew, Romanian, Slovak, Thai, and Ukrainian language support
• Address issues when using smart cards to log into OS X
• Resolve issues authenticating with directory services
• Address compatibility issues with Windows file sharing

For detailed information on this update, please visit this website: http://support.apple.com/kb/HT5048.

For information on the security content of this update, please visit: http://support.apple.com/kb/HT1222.

Or should I look for and download the Combo Updater?

If you are experiencing proboems with v10.7.3 try the > OS X Lion Update 10.7.3 (Client Combo) update.

What is your current system?