The Notary log file at INFO doesn't look to log any information relating to requests from other nodes to validate transactions ... the only statements I see are relating to AMQP connections, and updates to the network map. From an operators point of view, it's very difficult to trace flows through a network i.e. if a notary does not respond to a request, you never know whether it actually even received it. Requests of this nature are I believe logged at DEBUG, but this will likely be too verbose generally.
The log files should give high level meaningful information from the perspective of a network operator or admin. Succinct but descriptive to the business flow into and out of the component.