Sean
As you are well aware I'm a former member at Moray and no doubt you'll think me biased, which is probably true, but I've also had the great advantage of playing these courses a number of times and in different types of conditions. There is no doubt that Moray Old is the best and in my view most enjoyable course of the four listed and indeed I'm on record as saying that it is as good a links as there is in the north of Scotland, and yes that does include RDGC, Nairn etc.
How does that square with the respective rankings of Moray Old versus, for instance, RDGC you may ask ? I think there are a couple of reasons for that, firstly; RDGC and to a lesser extent Nairn have been "discovered" and the hordes/raters keep making the pilgrimage and burnishing the legend. In a sense it becomes a self-fulfilling prophecy and they rate it as they expect to rate it. The second reason, which I think you have succumbed to, is to either consciously or sub-consciously judge the design partly on the condition of the course when you play it. In this instance the state of the fairways was poor, due to issues with the irrigation system (who says you don't need sprinkler systems in Scotland !).
When you consider that Moray has two full size 18 hole courses, the same as RDGC, yet has about a third the number of green-keeping staff, you realise that keeping of with the Jones all of the time isn't possible. However I'm confident that if you were to go back to Moray during Moray Open week then you'd come away with a much higher opinion of the course. It would help also that you'd been before you'd be more familiar with the layout and the nuances would reveal themselves more second time round. Usually the sign of a very good course in my experience.
I do agree though that I wouldn't compare it with Rosses Point, although only because in a sense you would be comparing apples to oranges. Rosses Point is all about the green complexes as the land isn't as interesting whereas at Moray it is a mixture of the routing, greens, topography etc. That is why I think Moray Old is less susceptible to being weakened by the odd tweak. At Rosses Point, where the Lord Voldemort of GCA (you dare not mention his name or risk the threat of Legal action) is doing his thing, you have to fear that some of the magic will be lost.
Going back to the Moray courses, I do wonder if your preference for Covesea over Cullen has to do with playing Covesea first, in that the novelty had worn off by the time you got to Cullen ? Either way, if going back I'd urge you to play Elgin and Duff House Royal which are comfortably the 2nd and 3rd best courses in Moray.
Niall