2. xlockmore is a drop-in replacement for xlock.
3. xlockmore runs with just one command.
4. xlockmore works fine with xautolock.
5. xlockmore requires no gui interface for build, just vanilla X.
6. xlockmore has lots of system menus.
7. xlockmore feature where you can press the middle mouse button to "change".
8. xlockmore/xlock allows root to unlock the display.
9. xscreensaver does not have my favorite modes/hacks. "Life? Don't talk to me about life.", Marvin the Paranoid Android.