I love this book. I took grade 8 a long time ago and still love piano but don't have the time or energy to learn new pieces, so enjoy being able to dip into this book.
It's a wide range of music in v large print. Don't buy it if you want a song book (it's not sold as such anyway...) but if you're a tired lapsed pianist this still kids you into believing you can tickle those ivories as you always did. I have all 3 book in the range and actually prefer this one, the first one (red) because it's has the best choice of soft classics for me, but obviously that's a very personal thing. The 2nd and 3rd books are in much smaller print so I find them much less user friendly.
I believe the level is around Grade 5 (chap in a music shop told me).