tedster - 11:43 pm on Apr 1, 2010 (gmt 0)
I'm not sure what your goals are when you mention "usability" -- but I do some work through agencies, and for their clients who don't currently run any good analytics, they do recommend GA as an analytics package option. There is a lot to like, even beyond the "free" part.
I recently saw a report about the GA market share, and even among the top tier websites the number was surprisingly large - I can't locate that article right now but it was something well over 50% for top sites.
The GA reports just seem easier for middle and top management to configure and use. It's also rare for any company to use the full power available in any analytics package. They really need a dedicated analytics person (or even a team) to do the job well - coordinating goals across the many departments. Many companies do not yet appreciate the value in that.