Have just completed DL OAA course and passed all exams. The books are too detailed in some subjects so I bought Bristol Ground school notes from ebay for £80 and these helped.
Ops procedures OAA...dont waste your time with that one BGS was spot on.
Nav OAA... book excellent better than BGS.
Met OAA dvd and cross referring to OAA book got me a pass.
Law OAA ...at first hated it but all info is there but make sure you make an index as you go along with this book.
POF OAA excellent
Perf OAA.....crap use BGS
Loading OAA....Crap use BGS
Flt Planning OAA okay
Comm OAA...very good
Radio OAA... good
ect ect
TOP TIP: Buy 3 months of BGS online QB nearer to exams...all questions are there,in the actual exams it became a test of question recognition...easy, it was no harder than GCSE's just a lot of them. God knows why the airlines pay so much to their pilots !Hopefully I will find out oneday.