MGMAT CAT math will destroy you, unless you're a math genius! I am very good at math (got a Q51 on the real GMAT) and I never got over Q47 on the
MGMAT and never had time to finish. All my other practice CATs had Q49 or higher.
Verbal is roughly the same, so if you killed it, you're doing well.
Just add 2-4 pts to your
MGMAT Q score and that should be what you get on the real GMAT.
Make sure you take GMATPrep though, as that's the ONLY thing that is truly representative.