I have just purchase this book for my son. It has lots of fun exercises for him, has anyone used these books.

I'm using it. But I think I'll need a teacher to guide me. I do not understand some of it.

I've got it, but also found it confusing in places.

Probably my teacher is just as confused! Hence she did not want to try using it. But some parts like the wave and the polishing the string part were helpful. I got a bit of a feel now. It's easier to do vibrato in higher positions!

I agree. I hate first finger vibrato in first position.

No choice! A lot of music still requires the first position. Either your vibrato goes a bit pear-shaped or your intonation!