I have completed a number of online courses at tertiary level at a few different universities. I have also studied many subjects on campus aswell. There are definite advantages and disadvantages to online vs on campus study.
Advantages of Online:
You can study when it suits you. If you prefer to sleep late and study in the middle of the night, then you can do it.
You don't have to get dressed or even shower to go to uni (pew!).
It is much easier to make friends online as there are forums where you can meet others studying the same subjects. You can even find people in your local area to meet up in person. As everyone is alone at home there are always plenty of people keen to get to know one another.
Depending on the University, online content is often presented in some really interesting formats which make learning fun.
You can watch podcasts of your lectures when you are feeling alert (and you can pause them for cofee or loo breaks)
Disadbantages of Online Study
Despite the online presence it can at times feel very isolated and lonely studying on your own.
You need to be extremely self motivated to stay on track as there are always far more distractions and commitments like housework and kids competing for your time at home.
You often miss out on that in class experience of discussions and the ability to ask questions on the spot. Clarificaition of questions is usually more effective in person where you can have a real conversation.
The courses are often very time consuming as there is way more reading to do. You need to keep on top of forum discussions (which get seriously out of control at times), as well as all the online content which is mostly in written form. You must do all this and learn to navigate your way around the complicated learning sites. Then you still have to do the readings in text books.
You have to spend way too much time in front of the computer instead of getting out in the fresh air.
When you need a book from the library you have to search for it online then wait for it to be posted to you.
On campus you get to participate in all of the social activities on offer. The libraries are great resources for study and you can find stuff on the shelves in person. You tend to stay more easily focused because you are physically attending Uni so it becomes your only prioritiy. The motivation of an angry lecturer if you turn up without your assigned homework is very motivating.
However its also a lot more difficult to make friends on a huge campus where everyone seems to already know someone, especially when you are a minority such as a mature aged student. You have to turn up to lectures at the allocated times, even if this doesn't suit or you have other committments like work. You don't always get to choose your class timetable.
All in all there are benefits and downsides to studying either online or on campus. Some people are suited better to one or the other.
If you are considering online study make a list of the issues that are most important to you and think about how you learn best. This will help you make a more informed decision.