Although version 11.0.23 was primarily a maintenance and security release, it solidified the core capabilities that made Reader XI a preferred choice for many users:

Users could utilize a full suite of commenting tools, including sticky notes, highlighters, and freehand drawing, for collaborative document review.

Approximately 380MB to 450MB of available hard-disk space. End of Life (EOL) Warning

This update provided critical fixes for vulnerabilities identified in Adobe Security Bulletins to protect against malicious PDF-based attacks.