@mikepa I did not notice any latency or sound quality issues with the Sennheiser system. My experience was during a symphony rehearsal and the conductor did not have a microphone. Therefore, I was only listening to music, for the most part. I didn't notice any delay. The quality seemed fine to me but I do have a severe to profound loss. When your library has the Listen Technology system in place, ask people with mild loss or normal hearing to try it out and get their opinion. Since your venue is in a library, you may want to try the system when the computer network is in high demand, such as when all the computers are being used by other patrons.
Tony in Michigan