Metrics toolkit for assessing usability of archival websites

There was some discussion yesterday on the EAD list about evaluating the effectiveness of online finding aids. Wendy Duff drew attention to a project she is involved in, called 'Archival Metrics', which has put a toolkit together for undertaking user evaluation of online finding aids. There are also other archival metrics toolkits available for download. Am wondering whether this will be useful to us as interface developments become a larger part of our work.