I went through about 6 full length EK 101 practice tests and never did better than a 51/60 (which I think is an 11). Most of them, all except one or two, I got a 10. I didn't seem to improve at all.
On the three official practice tests I took, I got two 12s and an 11. I just took the real thing today and think I got a 12 or better, but who knows?
I do think the 101 passages are great practice though. Most of what I learned is how to identify questions that are likely to be less straightforward, and how to choose a best answer quickly and move on so that I could finish with 10+ minutes left to review all of my unsure answers. Well, that was mostly the computer aamc tests, but I still think the EK 101 passages were good practice.