It depends what you want to measure of course. I provided results to a variety of servers besides my local fast.com and speedtest.net server. As well, I'm familiar with what speeds I get when downloading Xcode, when pulling binaries via Usenet, etc. The results from Cloudflare indicate to me a bottleneck on their end, and something is especially wonky with the upload result.
I get 860-910 Mbps down/ 180-372 Mbps up to NYC[1-3], TOR1, but I have to test using Chrome. Running the DO test under Safari is pegging the CPU on a Macbook Pro 2.7 Ghz i7. (The other speed tests run fine under Safari.)
Indeed, their tests are currently wonky. I get 10% of my regular upload capacity, and 30-50% of my download through their test, despite testing to a Cloudflare location within the same city as myself.
I just wanted to ensure that we correctly discredited useless numbers and focused on the interesting ones instead.
Doesn't cloudflare also have boxes in ISPs? Youtube, Netflix, Facebook, Akamai, Cloudfront, etc all do. It's all relative.
fast.com likely has the exact same issue, as Netflix has content boxes at ISPs, although I can't say for sure.
Plus, even then, "speed" isn't absolute. It's all about agreements, routes, capacities and load. Test to specific targets of interest if you can, e.g. http://speedtest-nyc1.digitalocean.com/.