Ask HN: Recommend web analytics tool for a social listening platform?

hi, we are working on a social listening platform and have a dashboard with charts, alerts etc. and wish to optimize the UX to A/B test which features are most useful for our users through activity heatmaps etc. Not looking to go overboard, just a plain vanilla analytics tool seems to be what we need for now. Any recommendations on which web analytics tool we could incorporate? I know of Kissmetrics, Mixpanel, GA etc. Could anyone share their experiences with those ? or suggest ones that worked for you at a small startup stage? TIA