Quant is above and beyond the actual gmat & verbal is at par with the actua thing.

Manhattan CATs bundles comes with 6 cats.
Questions arent repeated unless you reset the tests. The reset can only be done upon completion of all the 6 tests.
TBH these tests give an accurate indication of the weaker areas and also to learn new concepts which may or may not have been touched upon during the prep phase.

Quants is way above the real thing and a q44 in mgmat can translate to a q48 or q49.

verbal is the same level as the real thing. Sometimes the language can get convoluted , but the quality of questions is excellent. a V35 and above can translate to v37 to v40 in the actual thing.

These tests should be used as indicators to measure timing and weak areas and are not to be used to predict the scores , doing well on these tests will definitely mean that you'll do well on the actual gmat but again depends on the test day and the test conditions.

Mgmat CATs are a great resource to practice and learn .