presspass
filmshooter
Maybe not for good light, but I shoot high school basketball for our weekly newspaper. 6400 certainly makes that job easier, even with a 1.4 lens. Do we need it - no. Is it wonderful for these subjects - yes.
Now, if only a manufacturer would add a dedicated ISO dial to go with dedicated speed and aperture dials, so that you can check at a glance the setting.
I push film to 6400 regularly. As soon as i get a MF camera I'll be shooting 12500 and 25000. Wooo!