The degree you get is the same one you would get offline from the University of London - in fact, you can transfer to the final year of the offline degree if you're willing to pay the (much higher) tuition costs. That suggests that the curriculum and marking standards are the same, in fact I believe that the exams themselves are actually the same as the in-person exams.

http://www.qmul.ac.uk/international/international-students/e...