A couple of points.
1. Under the GD system conditioning represents 12.5% (1/8) of the rating (7 factors with SV counting double). However, at times for sure conditioning impacts shot values. Yes, I know in theory it should not, but in fact sometimes the design can contribute to soft/slow conditions (insufficient drainage, L and R rough sloping down to the fairway, etc) and besides, we are rating the course not the design or the architect...maintenance can be as important as design.
2. There is one other important aspect of the GD system...clubs/courses can as that their ratings history be wiped clean. That is not an easy decision, as you can't be on the top 100 w/o 45 ratings in the last 8 years...and you cannot selectively erase...it is all of history or none. It can take a while too get to 45...not if you are in NY or LA but other places it is tough (e.g....Old Town in Winston-Salem).