We deploy little apps internally. Users have low latency on the network - even home users we steer to use ISPs we know have low latency. I've found that speed can make a difference in user like for an app. Even going out to google etc I'm currently at 5-6 ms.

Some things we might have 1000+ checkboxs to work through on a checklist (cut down by some initial tailoring steps). Even things with a small wait on a click etc are frustrating. If you can drive using a keyboard shortcut and get very immediate response you can really move through things.