I think you were unlucky with crowds at Fraser's, although you did very well for birds. I was there at a weekend and there were only a few. It took me 5 minutes to see the partridges well. I agree that TN was bloody hard work.
Can I add to the Merapoh area questions: do you have a recommended place to stay and is there a particular trail that is best for the railbabbler? Having spent many, many hours failing to see one a site where they are 'easy' is extremely appealing.