In general UIs should always respond in 100ms or less. For lord's sake GMail takes a full 3s which is slower than any desktop client took in 2000. Somehow people think it is okay to make your page slower because "ooh aah AJAX" and "oh I can just add a spinner" or something ...

Back when I used pine it just loaded instantly! No spinner, no splash screen, no progress bar needed.

And don't give me that "oh but it's in the cloud" crap -- the cloud isn't an excuse to be slow when I have a 300mbps downlink with sub-10ms ping times to headquarters and datacenters of these companies.

If you're used to fast paced web apps like Trello, yes.

It begs the question what could it possibly be doing to take half a second of wall time. That’s an eternity for a modern computer.