We've been working on bringing the mapping features that are supported by MapBox and Open Street Map into line with what you've been able to do with Google Maps for some time now.
The key feature that has been missing from our store locator software has been Marker Clustering. Well, the good news is that this is now available in MapBox and Open Street Map maps as well. Here's how the new marker clusters look on Open Street Map as an example:
At the same time as adding this new feature, we made some changes which have resulted in a MAJOR performance improvement when running MapBox and Open Street Map. Previously you might have found that these two platforms performed worse than Google Maps when the number of map markers exceeded 1,000; now these improvements have been made, MapBox and Open Street Map now actually offer BETTER performance than Google Maps for large numbers of markers.
Finally, we added the other missing feature from Google Map which is that when both 'Update store list when dragging map' and 'Limit markers shown' are Enabled, the store list and map markers are dynamically updated as the visible are of the map is dragged around by your mouse or finger. A very cool feature if you are interested in seeing this!
We've tested MapBox and Open Street Map with up to 100,000 map markers and the performance even on fairly low end hardware such as older Android devices is still excellent so these two platforms are starting to look like the mapping service of choice if you have a large number of map markers. It's worth mentioning though that as before, Marker Clustering improves map load times and improves performance when scrolling so it's worth considering when you have over 1,000 map markers.