Phillipe,
In my work, I have a few courses well further than the mainstream courses of urban areas where design/re-design seems to be a part of strong play. Among new courses, my MN stuff has done very well - a few years ago resort play in MN was down 6% overall but theirs was up 15%.
Near Houston, my Wilderness course has gotten 45K rounds of play despite being 60 miles south of town. And the local country club, which always struggled and lost all its outing business closed a year after opening....
And in DFW, my remodel of Indian Creek increased rounds by about 10K and the course(s) (it is 36 holes) went from $800K in losses to $300K in profits. Initially, higher play can be attributed to advertising/marketing and the new look of the course. As time goes on, I presume a lot of credit for continued strong play has to go to improved maintenance and service from a new management company, esp, since as time goes on, results are continuing to improve.
Now, its not all design. I think the best way to describe some of my mid level courses' popularity is "value." One gent stopped me in Minnesota to complement me on my courses there. While I was taking in all his rave reviews, afterwards it dawned on me what he was saying. He was a banker who entertained clients and at one point he says that his customers liked my courses as well or better than anything over in Brainerd (a big golf resort area) and he got to "golf 'em, feed 'em and sleep 'em" for the same price as golf only over in the more established area. A big win- win for him!
In simpler terms, another course manager put it like this - if you can offer the perception of a $100 course for $80, or a $50 for $40, you'll get a lot of play. Offering a course percieved as a $40 for $40 is okay, and offering a $40 green fee for a course percieved as a $20 course is death in business terms.
So, some mix of design, maintenance and service provides that option. For managers it means cutting out any service or nicety that golfers really don't appreciate. For supers it means letting the edges of the course go, but keeping greens, tees and then fw in great to good condition.
In design terms, a renovation probably means a whole new look....at least in America, products are advertised "new and improved". That puts a lot of pressure on doing changes that are visually based, rather than infrastructure that might help the super, even though new irrigation or drainage might improve maintenance more and usually makes more sense.
It also raises the question of how you design - you might love blind shots, but if the local clientele is not in favor, do you include them to "educate" them? Do you restore a course to its original (and possibly dull, in the players eyes) design, or give it a fresh look that will drive the curiosity business? Do you put in features your client can use to get customers like waterfalls, landscaping, etc? In golf, like most businesses, there is a fine line between offering the perfect mix and one that is way off target.
I presume that varies a bit from market to market, and its worth looking at the big picture before starting design. I visit competitive courses before starting a design or redesign to "benchmark" what I have to do to make my owner's course competitive. If my site is bland compared to those of competitive courses, I might focus design on unusual holes, because there is little sense in having the second most aesthetic course with traditional play values in an area. Better to have something different, IMHO. If most courses are new, I might focus on more traditional design so the course stands out as being "the best of its type" in a region. I used that approach at the recently discussed Sand Creek Station, and thats why I came up with those adaptations of the Alps, Redan, etc. holes - the other courses in the Wichita area were nothing like that and I thought it would do well.
I offer these examples because I sense your course is "mid level" like these examples. There is no sense in offering up Pebble Beach, Sand Hills, or one of golf's other truly unique experiences as an example of what might happen in your situation. As always, I could be wrong.