They are very good for overall review. I wrote 5/21 and am using them as a refresher until I hear about my scores (I am signed up for 7/16 in case I bombed it).
Overall, I would recommend them, BUT there are numerous errors. Actually, a lot of them. You may not catch them because they are subtle, but EK has been known to have a lot of errors in their printed books.
Also, the accents are annoying. Sometimes, their pronunciation of certain chemicals or biological concepts can be a bit strange. This is just a nit pick, but if you are going to listen to them for 12 hours, their accents can affect it.