IMHO one of the strongest features of OCS is its adaptive Audio codecs and the Quality of Experience (QoE) approach to sound quality.
The QoE whitepaper available for TAP's, MVP's and others has now been RTW'ed -
This document introduces Microsoft UC Quality of Experience, an innovative approach that aims to provide all users with the best possible quality anytime anywhere. It combines a comprehensive, user-focused quality program incorporating all significant influencing parameters; the use of intelligent, adaptive end-points that have the real-time capability to monitor, pilot, optimize, and deliver the Microsoft UC Quality of Experience; real-time metrics of user’s perceived quality of the actual call experience for all calls, collected in Metrics CDR and processed by a UC Monitoring Server; and a new media stack optimized for unmanaged IP networks, capable of real-time adaptive and corrective actions to continuously optimize the user’s subjective experience
It's a very good whitepaper, a bit marketing oriented but still contains a lot of good info on the QoE approach and especially the Audio Codecs and also the actual network bandwidth usage (IMO there could have been more info on Video - but you gotta stop somewhere).
Find it here (Seen on Tom's blog).