I did 180 (240 but I deferred one module) credits in two years at the Open University and now I am transferring 120 credits to a brick uni. As I live in Wales it wasn't that expensive but I wouldn't do it in England, it's just not worth that money.
You will get very limited support, you will be more likely on your own and grading is a little bit too harsh. For example, I was doing 60 credit modules and it means that if you will fail one assignment or not score enough, you are instantly one grade down. Also, the final assignments are usually worth around 50% of your final grade so if you won't perform very well, it can take you from B to D.
You need to get at least 85% to get A and it's kind of impossible.
If you will have a problem with the assignment and email to your tutor, he will answer you to read student notes and will ignore further emails from you.