I'm taking the 8/4 test too! But, I'm really considering changing it to Aug 10th b/c I want an extra week just to do practice materials, before doing only full length tests and minimal content review for the last four weeks...but I'm undecided right now
I think the verbal assessment was very helpful and excellent practice. I've done a few of the EK verbal tests, and they are definitely different from the AAMC ones. I would say do the AAMC ones, and if you have time/feel like you want extra practice, then keep doing EK ones after. Also, IMO the TPRH passages for the most part were somewhat easier than the AAMC ones, but that's just what I thought!
I took them as three separate verbal tests, so 1/day for 3 days. I did time them, but they didn't all even out to 40 questions for 7 passages, so if there were more, I would add 1 min accordingly. Also, it's very helpful to see the categories of questions (application, comprehension, etc.) and level of difficulty (easy, medium, hard) that you got wrong so you can improve on them.