This is maybe one of the best extensions they ever exists for tracking and analyse the behavior of you site vistiors. I bought it one year ago and I can't compare it with other tracking software such as google analytics and piwik. This one is thousend times easier and get you exactlly the input to know what users are looking for in your site. The best of all is the great support from Developer Site to face issue in less than one hour and its assesment for our specific problem.
This extension is strongly recomment and will be very usefull before make any change in your site structure in order to reach better expirience for users... with google something impossible!!