I haven't used eCollege or Blackboard, but I have used Moodle (as a student) in a couple of courses, and to be honest I found it to be a stunningly mediocre. If it really is miles ahead of everything else then the whole concept of that type of software probably needs to be radically rethought.
PS: I should add that this was a good 3 years ago, so great things may have happened in the meantime.
PS: I should add that this was a good 3 years ago, so great things may have happened in the meantime.