I started preparing around January and CET preparation without SimCET is incomplete. This is one of the test series that maximum aspirants purchase and that helps to gauge your performance vis a vis others more accurately. The quality of questions and varying difficulty levels of mocks prepare you for any kind of paper. The experts take after the mock helped to understand the correct strategy that should have been adopted, the mistakes that can be avoided and the type of questions to look out for.
Lastly the analysis is the best that I've seen until now. Since CET is a speed based test, time taken per question by you vis a vis the top 10 students, accuracy of top ten students. The solutions also highlight the shortcuts that can be adopted especially in Quant and DI. All in all this is one test series I would recommend every aspirant to purchase.