I used the OAT disks too... Yes they are expensive, but a very helpful tool if you ask me. They present the subjects in a very clear manner, animate various topics (Great for aircraft technical) and you can go over the bits you really don't get again and again and again... without paying for any more ground school or frustrating your instructor! (Although my instructor was amazingly patient with me - legend)
I am planning on heading down the ATPL route and am seriously considering the other CD's they produce...
Again, I don't work for them, I just have my opinion
