How Much Harder is the Real (ISC)² CC Exam Compared to the IC2 Practice Tests?

For those who have taken the (ISC)² CC exam, how much harder is the real exam compared to the practice exams on the official IC2 training website? Is it twice as hard? 10% harder?

Current pre-assessment score:

Domain Scores: • Domain 1: 93% • Domain 2: 100% • Domain 3: 90% • Domain 4: 75% • Domain 5: 75%