Squiz were exceptionally good at building and launching our website. They understood our requirements and translated them into a realistic backlog. Where we hit areas of difference, we had professional and effective discussions to find suitable compromises.
User Interface was good but heavy, with Java powering the backbone I recall finding this somewhat troublesome at the time.
While working with Department of Primary Industries we integrated squiz to host all internet based services, including the intranet. We felt that this CMS addressed all of our requirements, heavily focused on standards, best practice, highly customizable distributed publishing while allowing for scale. I believe the platform is still being used today, now around 7 years later.