This makes interesting claims about performance but doesn't describe them. Are they all based on client-side javascript and graphics efficiency? I ask because

This makes interesting claims about performance but doesn't describe them. Are they all based on client-side javascript and graphics efficiency? I ask because it seems to me that the most important thing in map client performance is the ability of the tile server to quickly and consistently deliver tiles. Especially important is the tail latency. To experience this for yourself go to the Leaflet preview page[1] and change the base layer provider. It will be several seconds before all the tiles are drawn, even for several identical tiles in the middle of the ocean. Most of the tiles arrive in the first second but out of a hundred tiles on the screen there are the inevitable stragglers. And sometimes it just doesn't serve at all[2]. 1: http://leaflet-extras.github.io/leaflet-providers/preview/ http://leaflet-extras.github.io/leaflet-providers/preview/ 2: http://pasteboard.co/8bnyEPXGC.png http://pasteboard.co/8bnyEPXGC.png