I thought it was pretty tough. I had taken the MCAT Practice Tests 3 and 4 (the ones actually put out by the AAMC), and thought they were much easier.
I got really frustrated with the Biology Section (I had the test code AG with serial number 30300? or 03033?) because it had SO many genetics questions! That is one of my weak areas, and there were like 15 questions on genetics!!
I also thought verbal reasoning was tough, and physical sciences wasn't that bad.
I had been getting all 11's and 12's on the practice exams, but I don't think I did that well today. Have to wait and see, though.