I reviewed this site for 30 minutes. The quality of the content was very good. It followed a course set up by the instructors. It appeared to be easy to navigate for those taking the course. As for those generally interested in virology, it was good and relatively straight forward. The associated links were helpful and yet not too cumbersome (i.e. not too confusing or distracting). The user interface was in general, easy to understand.
It might be useful to have some streaming media effects added-e.g. viral infection of a cell or nucleic acid replication with in the cell). But, this web site was excellent for those with a 56K modem. The first time user should find this site easy to use.