For our clients that are investing in a paid analytics platform, there's a great return on investment since they fully leverage the features and integration that those platforms offer above and beyond Google Analytics.
That said, we don't have anyone that's NOT running Google Analytics as well, though. Why? Because Google Analytics has the unfair advantage of integration to Google+, Webmaster and Adwords data. Of course, it has the unfair advantage of not having access to Facebook data – the largest social interaction site in the world.
From the American Express Open Forum article, Decoding Google Analytics: If you are Web savvy enough to register your business site with Google Analytics, pat yourself on the back. But how much do you really know about the data you're receiving? What improvements can you make based on that feedback? Here's an introduction to key metrics to help you get more clicks and get customers to buy.