I am nearing the end of Distance Learning. Did 8 exams in feb and passed all, final six to be done Dec/Jan.
I am afraid Distance Learning is a long hard slog, with no substitute for time with head in the books. But it can be done and when the CAA send you the bit of paper saying you passed the feeling is incredible, one of the best feelings of achievement I have ever had.
I think it is best to do one subject at a time. This avoids having to go back over stuff which wastes time. It also allows you to finish a book and put it on the "completed" side of the shelf. I started the course how the training provided advised which was something like this:
Chapter 1-7 of PoF
Chapter 1-5 of Systems
Chapter 1-4 Perf
Chaper 1-3 Mass and Balance
Chapter 1-4 Air Law
etc etc etc
Trouble was after three months of hard study no subjects completed, it felt like I hadnt got anywhere if you follow.
The brush up weeks are vital for DL and you must know your stuff when you get there. Feedback questions are vital too. LGU (who I am studying with) are very good at providing feedback now, and I would say that without the feedback you will struggle to pass the exams.
As you get through the course you will find though that at lot of stuff comes up in different subjects. Namely a lot of stuff in air law is repeated in Ops and Procs and Flt planning. So if you can learn it once and retain it, the "what is lowest DH for a Cat 1 approach" that is in several question banks can become money for old rope. There is quite a bit of overlap in Instruments/Gen Nav with regard too magnetic compass and IRS etc.
PM me if you want any more thoughts or help. Good luck.