This assumes that Google's CDN is providing a significant advantage in connectivity, when in actuality you'll often have more available bandwidth between say OVH and your ISP at peak times, as compared to relying on Google's congested peering to certain large ISPs. Amazon S3 can be really paimfully slow at peak times too, I often see sub-1MB/s, while fast.com (Netflix) or OVH can fill the pipe.