In reply to bojan, I thought I gave several reasons for choosing a De-Rotator. Also as I mentioned I will also be using a Wedge. It's fair to say that if you want to go shopping you dont take the truck, but you may need a truck. I have also had a great deal of trouble finding a person that is able to assist me as I was learning, so a De-Rotator for me got me in the action fast. I found it far easyer to get results that I was happy with. My main point is also that a De-Rotator does do what is suggested. Exposure times of 15 - 20 mins with upgraded Peterson Gears. I don't think we will all ever get a diffinitive answer, but I an more than happy with mine.
Mardy