There is no doubt that Bob has introduced many people to oil painting and his style of instruction is very good to give confidence to beginners.

However, the statement 'this method does not work with any other paints' is HOGWASH. Its a wet in wet technique which has been around longer than he ever was. I make my own type of liquid white and liquid clear and use ordinary oil paints, and they work just fine.

I have watched Bob's shows and the painting are very chocolate boxy and not, in my opinion, at a high end craft level, I mean, he does not compare with Turner or Constable does he?

I agree that Ross's technique does not allow for highly detailed paintings. He, in my view, was simply trying to introduce a technique which would allow beginners to create respectable paintings without years of practice.