In my experience and from what I've read on the forum Knewton CATS are harsh on your quant score and too nice on your verbal.
I used to finish my Knewotn Verbal sections with up to 15 minutes left and scored in the 99th percentile on my last CAT (also about 15 min early)... on sunday I scored in the 77th percentile for verbal on a
MGMAT test with no time left over - doesn't make much sense... on other MGMATs I have never scored above 93% and have never had time left over. (Josh I messaged you about this, any news?)
Quant on the other hand seems a bit harsh, I never scored above 43% on quant on Knewton CATS, but I consistenly scored about 70% on the
MGMAT exams....
Having said that - I think the questions are fantastic, I am currently doing the OG and I feel like I have already seen 90% of the questions - Knewton did a good job mirroring Original questions I am quite a bit relieved, I thought the OG was going to be a pandoras box of sorts, I didn't really know what to expect!