I found that the OAT CD's were very crude in their production and could really do with an update. The graphics seem to be very outdated and it doesnt appear that they've invested much into the production. I found I learnt twice as much with the AFE books compared to the CBT.
If I could I'd return them and spend my cash on a decent set of shelf fillers. The AFE PPL books have a fresh appearance and have lots of good core information and are not dictated to you in a very monotone and boring voice.
You can tell I'm not fond of the OAT CBT!
S88