Official GRE Guide mock test

Has anyone solve the mock tests from the Official Guide?
How was it comparable to the real GRE, score and difficulty wise?
Is it a good idea to give this test to understand your score and where you stand, even though the number of questions differ?

I asked Leaderboard the same thing , He says its a fair representation
Found it a bit tiring though doing 2 verbal sections together

Oh alright
I didn’t manage time well, and so I wanted to know if the tests are similar to the actual GRE.
Thanks!