Yep. I can supply BST. I fitted a set to a customers R1 a few months ago.
These things are absolutely stunning. I spent a hour, literally, going over the wheels and checking the detail in them.
Price wise, a little over a grand for the front and £1400 or so depending upon the width of the rear.
The feedback I got on the R1 was similar to Stephens experience. Pin sharp turn in and improved front end feedback were the main ones. The bike is on it's ear and round the corner without thinking about it now.
The owner is also convinced that acceleration/braking has improved to.