It's a pretty good source ime (at least, massive spikes tend to correlate well with issues). Traditional organisations aren't as transparent as SF tech companies about service downtime. Plus, if the service isn't working for its users, I wouldn't say it's actually up.

Exactly. "Responding to pings" is not the same as "letting me get work done".

If I had a nickel for every solid-green status page I shook my fist at while the actual site faceplanted on every request...