I just posted a list on Facebook of the
Top Course Collectors in the World, so I believe that this is now the most up to date and current listing. (NOTE that this is a work in progress so it is currently not complete.)
DGCR has the most authoritative automatically generated list, but it does not include courses only listed on Udisc or Private unlisted courses so every course collectors "Real course count" is undoubtedly higher.
To get to the Udisc Leaderboard on your phone follow these steps...
1. On the bottom menu select "... More"
2. Select Leaderboards >> Player Records >> Courses
That will give you a list with derektonn at the top with 1935, but that is because the Udisc list is not complete since many course collectors don't have their list up to date.