I would say it's just different than Google Analytics. GA (as you know) allows you to really analyze your data, identify trends, etc. Visitor Track pretty much gives you a list of who visited your site, the keywords they used, which pages they viewed, etc. It has some reporting capabilities, but nothing like what GA has.
Visitor Track is almost more of a sales tool, so you can see which companies are visiting your site. Then you can try to go after that business (but again, you have no idea who at the company was on your site - it could be an intern or it could be the CEO).
I've really just started looking at alternatives. Marketo has some really neat tools, but they're part of a larger lead management suite.
Here are some others - I haven't looked in depth at any of these yet, so let me know if you find anything out!