I found some of PPSC's DL material for the PPL/IR a little dry, and could have been explained better. However I think that if I were to do a JAR ATPL correspondence course, I'd definately be considering PPSC again (but I'd ask to take a look at notes from other schools as well).
That being said, the brush-up course was excellent. It really did pull everything together- the instructors there are very, very good and really know their stuff. They must be doing something right if a doofus like me can get a first time pass in all 7 subjects!