[Orgmode] Understanding habits - org-log-done

[Tommy Kelly]

For habits to work, he manual says that "You must also have state
logging for the DONE state enabled". My experimentation leads me to
believe that the state logging must not only be enabled but it must be
such that org-log-done is set to 'time and *not* to 'note. I tried the
latter and it doesn't seem to be interpreted as a state change. 

Is that as it should be?

Suppose I want to keep a note. Maybe it's "Go for run" and I want to log
time or distance. Is that possible?

thanks,
Tommy