In a, thankfully past, role working remotely for an antipodal organisation with badly configured networking; often, the lag between typing several characters on the keyboard and those characters appearing on my screen could be measured in seconds! Vi key bindings were a godsend as I could send commands (eg global search & edit etc) and be confident they were being applied before recieving a (delayed) visual update. I feel my experience seems to echo (albeit slightly) that of Bill Joy's vi development on a 300 baud modem!