Just cannot put my hands on an old training diary right now but I recall the first time I did Waiatarua, Pace/Time was not a factor. One of the guys ran with me all the way. A couple of the 'old hands' (George Gibson and Bruce Harrison) were concerned that it was run comfortably and easily..
I always laughed about our long runs especially where Arthur says 'Relax with the customary 10 to 15 mile jog'.
Interestingly, some of the guys would say "We're not going fast enough". The retort would be 'Where does it say "How fast" . This is a relaxing run'
But as for flattish courses. I don't believe I have ever run a long run on a 'flat' course here in NZ !!. Even the guys who live on the 'flat' in Christchurch would run in the Port Hills.