Tom,
Agree 100% on the necessity being the mother of invention, and on working harder leading to better golf holes.
I have always found that some strong general direction, with me filling in the details at will leads to my best designs, so Yes, the nature of feedback is important. A weak overall owners vision, supplemented by a lot of detail requirements, is usually a recipe for a not so inspiring design. I occaisionally have people out to the site, but rarely take advice from others than the Owner or his rep, my staff, etc. Not that a great bit of advice doesn't come from some really unexpected sources from time to time.