Yes. A lot depends on the university. I did post grad studies in education & communications at one uni - distance ed - and they created a great supportive network that fostered learning. For a self directed learner like myself, I just thrived and use what i learnt all the time. They created a lot of online discussion and interaction with the students, which was helpful.
I did a masters in international community development at a different university and the resources they provided were poor, there was little support - they seemed to want us for our fees, but please don't disturb us, just submit your papers.
Pros - flexibility for someone working full time.
Cons - You have to work it out without talking it through most of the time. It's hard to know if you're on the right track - have to trust your instincts and analysis.
I know the most advertised is that University of Phoenix. Some of my colleagues tried it but could never finish. I assume it must be hard, but I have to worry about its credentials. Many in the business world do not really look upon online degrees as being "real". Not to say the degree isn't real or isn't accredited but its just not looked well upon as compared to a degree you'd attain at a physical / recognized college.