For me Google Maps is slower than OpenStreetMap anywhere in the world, cache or no cache. Might have something to do with not using Chrome, where Google makes their websites work the best of course.
What do you mean by "the lack of precise zooming is super annoying"? In my experience, zooming in Bing Maps and OpenStreetMap are very fast, and only in Google Maps you're waiting ten seconds for the region to load and browser to respond before you can zoom further.
On Google Maps, your zoom factor is any real number within a range. On Open Street View, you are stuck using one of several predefined zoom levels (integers 1-20).
Google maps also changes the zoom level to the nearest integer. You can't do 12.5 for example. When I change the 10 on the google maps link in your comment to 10.5, it rounds it back down to 10 and rewrites the URL. Have ran into the issue before doing custom maps for sites where 14.5 would be the perfect zoom level, but can only pick 14 or 15 :(
There's vector stacks using OpenStreetMap data, I guess it will be a while before one is in use on openstreetmap.org.
Mapbox has one, Mapzen has one, various apps have their own vector map implementations, there are convertors that take OSM data and output maps in the custom vector formats used by GPS devices and so on.
What do you mean by "the lack of precise zooming is super annoying"? In my experience, zooming in Bing Maps and OpenStreetMap are very fast, and only in Google Maps you're waiting ten seconds for the region to load and browser to respond before you can zoom further.