GMAT Focus scores

I bought the GMAT focus quant set (3 tests). I took the 3 tests and observed the following:

Test 1:
I had 5 out of 24 incorrect. I fought to complete the test on time and my errors are uniformly strewn throughout the test. I found the test quite challenging as well. GMAT focus reports a score range of: 47-51.

Test 2:
I got 1 out of 24 incorrect. I finished the test with 5 leftover minutes! (Wish they would rollover to the next test:o) I found the test very easy. GMAT focus reports a score range of: 48-51.

Test 3:
I had 2 out of 24 incorrect. I finished the test with 8 leftover minutes. I found the test very easy like Test2. GMAT focus reports a score range of: 47-51.

I would rate Test2 and 3 at the level of OG. Test1 was more like a typical MGMAT.

I was hoping that the second/third test would be a tough one too. Else it is just a waste of time and money. If the tests did adapt, I cannot understand why they did not throw some challenging questions. The # of incorrect answers and the score ranges also do not seem to correlate.

Anyone see similar results? How did people using GMAT focus score in the real GMAT? Any comparisons with MGMAT performance? Please share your experience.

Thanks