Geospatial technologies evolve quickly, here's a fresh comparison of web mapping API and libraries, Testing web map APIs - Google vs OpenLayers vs Leaflet.

From the conclusion: "Google, for example, can easily insert adverts into its maps without us knowing. Leaflet and OpenLayers, being open source, cannot. That said, if your aim is just to get attractive 'off the shelf' maps up quickly, Google Maps is a good option. OpenLayers is mature and big and works well with servers. Leaflet, as the new kid on the block is the most exciting for me and encapsulates many of the benefits of open source software in general: speed of development, flexibility, efficiency. […] Lightness considered, for me that would mean Leaflet for many applications, but watch this space for the final version of OpenLayers3 (due very soon) and perhaps even better web mapping options."