Insight is Google Analytics on Steroids. However, there is some built in functionality in GA that would be cool in Insight.
The Recency and Frequency dimension in GA adjusts/recalculates to the timeframe selected. I can get at the same in Insight but would need to redefine the dimension for the time frame I want to consider.
Engagement by time - would be nice to get buckets
FREE Geocoding - ya I know it is there as a paid product - just thought I would throw it in there - we currently use Google and apply those percents to the Insight numbers
My point is - GA is free and has some cool built-in functionality that would be very useful in Insight.