The price of the simulator being at the higher side, I felt it has sufficient questions and in line with the real exam.
I bought it 10 days before the exam as it was released only recently (in first week of july) and the only feeling i had after passing the exam was to spend more time practicing mock tests.
The main reason i had bought whizlabd was thats the only one available at the time. So i will not be able to providde comparative analysis to those deciding on whick one to buy but i will suggest to buy one at the initial stage of preparation unlike me in the last few days.
All the best to all for you preparing for the exam.