People will argue that ajax.googleapis.com will be loaded anyways and that its jquery JS file will be cached but I'd argue that there are so many different Java

People will argue that ajax.googleapis.com will be loaded anyways and that its jquery JS file will be cached but I'd argue that there are so many different JavaScript frameworks with so many different minor versions, that the caching aspect isn't that good. There are also at least a dozen different popular CDNs for this and everybody is using a different one. The only thing it got going for it, is the bandwidth savings for the original website.