It's not easier than on campus. The curriculum is the same, and it's taught by the same professors and on campus head TAs (usually). If anything, it can be more difficult due to lack of interactivity in lectures to clarify things - although on the whole the recorded lecture quality is very good. OMSCS is no joke! If you want to take it, keep in mind it is a top 10 program and the workload and intensity of the classes can be very high. You will learn a lot, but it will also mean personal sacrifices (free time, time with family and friends) to keep up.