I took an
MGMAT CAT today and had a very similar experience during the quant... questions were all "hardbin+", with several additional levels of "resolution logic" necessary to solve most of the problems than one would see on the OG. Nuts. But, since I already allocated the time for the practice test, I decided to trudge through it, at least to see if I'm solid on my timing.
When I finished the quant, I didn't have enough time for the last question and felt like I got about 50% right. Since my practice on the OG is around 90%, I was slightly shocked. Brushed it off. Took the verbal.
When I finished the entire test, I put my palm to my eyes and peeked through to see the result (first number 6? 5??)... 700!! Yells, screams, and jumping ensued, followed by a look at the rights-and-wrongs, and as expected, I got over 30% wrong on the math but I rocked my verbal. (I have an engineering background, teehee.)
Moral of the story:
MGMAT CAT is not the best practice CAT option, definitely not for your last couple of weeks before the test (now I know!)... but it is still decent practice for timing, endurance, and a little bit of variety. If nothing else, it will make the real thing seem easy =)