It took 700ms or so for my server process to even start on a r.pi - I'd noticed a brief delay on my laptop, but it was so awful on the pi that I ended up spending the whole weekend profiling and optimizing. Anyway, come Monday I pulled the changes onto my fancy laptop and they made a noticable difference in subtle responsiveness. Everything just felt faster. I probably wouldn't have even noticed if I didn't spend that time programming on the pi.
Facebook has "slow internet thursdays" or something, where once a week developers can opt in to experience their internal facebook dev environments in the same way it feels for people on slow connections in poorer countries. I think that sort of thing would be good for all of us. Programming in constrained environments makes our software work better everywhere.