You make a fair argument. Google has several state-of-the-art JS applications. I thought of Gmail in particular because it probably sees much higher demand and so matters of optimization are probably a bit more important to it. This makes the amount of network activity, client-side caching, etc. it manages really impressive.
But no doubts that Google Docs is in the same ballpark.
But no doubts that Google Docs is in the same ballpark.