No numbered rating. On the one hand I'm enjoying it and learning a lot, but it's also pretty low quality in a lot of ways.
The exercises consistently ask you to do things you haven't been taught: mostly asking you to use vocabulary that isn't in the book, but also fairly often to reproduce points of grammar that haven't been explained. A lot of the exercises got messed up in the editing process as well. There are some with more answers than questions, or picture-based ones with answers that clearly don't relate to the published picture. I also found one or two errors in the English grammar, which doesn't exactly inspire confidence.
I'd still recommend it though. Better than most of the competition I've seen, and on a very handy single volume.