I have also subscribed to aviac. (
www.aviac.com)
I would say it is useful but the maths questions - 25 in 12 mins without a calculator - can't possibly be realistic. It's possible to answer 25 in 25 mins without a calculator but to be able to answer 25 in 12 mins I can just about manage it with a calculator.
I am pretty sure that some of the math questions have errors - not all but a few.
Have you tried Numerapt from cockpitweb too?
My advice is that both Aptitude and Numerapt from cockpitweb are good value for money.
It would be great if any other people with experience of PILAPT could chip in here.