How well 7 Learning Management Systems integrate with Google Apps

I recently looked into the way that several LMS (CourseDir, Engrade, OpenClass, Moodle, Schoology and Edmodo) integrated with Google Apps.  CourseDir, being a Google Product, won handily.  There wasn't a clear second place winner, with Engrade, OpenClass, and Schoology competing for that spot.  Moodle and Edmodo fared the worst (again, integration with Google Apps being the most important consideration).