The open question is would it be better or worse without AMP? It's likely that reddit (for example) would have just deployed an equally frustrating "mobile" page that loads even slower.

I just tried fetching http://www.reddit.com/ in an incognito window (no personalization) on a fast connection and it took 1.2s to get the first byte on the connection. I can't say if this is typical, but the AMP Cache has much faster delivery (~30ms) even before considering the preloading.