I got the Oxford PPL set, and interactive CD ROM and all books, I would say it was very high quality. Sometimes was good when tired to watch the CD ROM's - as they was very good for me.
I was working and going trough all 7 written exams and RT practical exam from mid September until around mid November, go trough one subject at the time and finish the exam as you go along.
I took the one I considerd the most complicated first, Principles of Flight, Mass and Performance was easy second exam, read 4 days on that, Air Law, Human performance, Met, Nav, RT - and RT practical - in my opnion makes sense to save Nav, Met and RT latest before you start flying, as this what you going to need have as fresh as possible.
Took me 6 weeks to do all exams, from first was started. And my brain was old and slow + I had full work commitments.
Compairing the AFE and Oxford books, I have to say the AFE are really boring - altough the Oxford is probably a bit overlearning - but if you going to do the ATPL after, then better to overlearn - Oxford books far more graphic - used AFE question book, and PPL confuser + Oxford questions.
Principles of flight exam, 50 questions finished in 10 minutes, not one error - had seen most the questions in advance in the different questions banks.
Nav is the hardest one, not because of the questions, but because of the time available.
Mass and performance, Human Performance, RT are relative easy exams.
Also the doing it quick and just learning the questions is not the right way - you cant learn one subject in one day - you need to know the subjects as you will get these questions during your practical training and skill test - one thing is to know the answers, but you also need to understand the subjects - because one day that knowledge or lack of knowledge will save your life, or if not knowledge - that will kill you!