I can confirm this. 98% of my upland hunting is for roosters but once a season in late October I go grouse hunting in Northern Minnesota and the number of grouse I've put in the bag over a decade can be counted with one hand. People that consistently put grouse in the bag impresses me. Those things get up and most of the time, I don't even see them. I just hear them with a whirrrrr of wings. In the rare case that I do see it, I get off a terrible shot in thick timber or brush. Every one of those things is a prize worth 10 times more than a rooster for me.
A well trained pointer would be an invaluable asset in the grouse woods. I have a lab and she works close, but its still very difficult. A pointer that held would allow a hunter to get into a good shooting location for a reasonable shot more often.