Ok. But not Great

I have been using the GMAT club tests for last few months

Pros:-
A very practice for the GMAT Exam
The quality of questions are good. especially in Quant
Scoring algorithm of Quant seems close. Infact, the actual GMAT score is atleast 1 point more as compared to that in these tests.

Cons:-
Did not like the Verbal segment of these tests.
The scoring algorithm looks flawed. I have seen absurd results for in tests ranging from 20 to 25, when i have been scoring in between 30-33 in the gmat prep tests.

The RCs asked in the latest 65 min format have 5 questions each. I am not so sure whether 5 questions come in a RC in actual gmat. I have taken all the gmat prep exams but never saw 5 question per RC.

Overall: Its good for practice, but the test might not be close in estimating your actual score.