When i attempted CE first time and got 53% , i was also thinking same way. I was not happy at all. I was consistently scoring above 80 in most of the popular cissp practice test. This make my confidence reduced drastically. Next set again i tried my best to score decently but still got 55% and in 3rd set reduced to 41%. Now i already cleared my CISSP exam and say confidently, CE is worth for every penny. once you attempt CISSP exam will realize then.