I'm a mature student *waves* but doing my degree through distance learning. I work full time and study one module at a time. I was able to use a professional qualification so I'm doing a Top up degree
The benefit of my course is that the majority on the course are mature students and most work full time. I decided to return to university (I dropped out due to health issues and looking back, the course was not right for me) as I found that many jobs that were being advertised were asking for a degree. Whilst I could argue that I had the equivalent through experience and professional qualifications, it hindered me to go for jobs and I also wanted to be able to say I have a BSc.
The hardest part is studying after a stressful day at work. I don't have children and I have no idea how those on my course can spend time as a single parent, study and work, I think if you really want something though, you find a way. The other challenge I have found is that little voice in your head that says "am I good enough?" I still doubt every assignment but having the support of my family really helps on those days.
For those thinking of doing a degree especially online, I would say have a clear structure of when you are going to study. Make a note of important deadlines and adjust your schedule for non moveable events. Finally, believe in yourself!