I was questioning this. Anything under 200 is "almost" instantaneous. Ideal would be less than 100ms, but you would need to have your server very close to your users.

For most users, the server latency in a good location will be 20-50ms, mid range will increase to 70-100 and far away locations will usually yield 150-500ms

This is just the server latency, without considering the time it tooke for your server to complete a request.

Let's say you have a really fast server with 20ms response times. In the end that will end up with response times of 100-200ms if users are not really far away from your server.