I just want to take some time to give a genuine review of GMAT club tests. I wrote few tests on US holidays recently and also I was given complete access to CAT's after subscribing to their youtube channel. From the test experience I had, I would say that if one is able to get 720+ in GMAT club mocks, then definitely they can manage 740-750 around in real GMAT. I can say this confidently based on the difficulty level we will be trained from their mocks. My first math CAT gave a score of 50. I was impressed but later it became 49,47,48,49. The moment I saw 47 I realized that I need to pay more attention while solving rather than being confident in my math skills. Though one knew all math concepts, still it depends how we apply them at the correct time and with the correct strategy. This is what I liked the most in GMAT.
Finally, if anyone is thinking which mocks to take for a good hands-on experience of GMAT, then GMAT club CAT's are more than enough to have a score of 740+. All the BEST!!!