You know the joke about "... it ain't rocket science...." Well, Saunders ("Saunders Engineering") was a rocket scientist. That's why his stuff is all about laminar flow and great stuff it is.
The edging works almost exactly as advertized and will budge the airstream 2 inches (but won't budge the rain and bugs quite as much for obvious reasons). It might just save your hearing. Hint: all you have to do is take your glove off and feel the location of the turbulent airstream to know it works.
There's no need to wrap the whole windscreen with the edging (and which of course can add to the frontal swept area, or so I would guess, and in places not desirable). So you can install a foot of the stuff only where you want the bump-up (up top, facing your head, eh). Granted, it won't win any beauty contests but maybe even more obtrusive when you use just a wee piece on top.
Various windscreen issues including Saeng edging are at:
http://tinyurl.com/6bvt23
No one has ever made a more beautiful or effective fairing than the now-rare Saeng unit (which I installed on the stock fairing bracket on a 1984 RT) and I include Hannigan in that assessment.
Perhaps a bit pricey, but good quality materials and nice people run the company.