I agree that the OP's summary of the best restaurants in Grand Case is accurate. And we will be eating at most of them this current trip.

However, you are also correct that Auberge Gourmande's food is superb. I put it in the same class as Pressoir and Sol e Luna. However, the price at all three is commensurate with the quality.

So even though we eat multiple times at Piazza Pascal and Le Cottage every trip, we would rotate between places like Auberge, Pressoir and Sol e Luna. Going to only one a trip.

So it depends on how the OP wants to balance their spending.

All in all it's pretty hard to go wrong with the list th OP summarized.

If I had to pick only one right now I would probably pick Sol e Luna simply because it has just been renovated and it is absolutely lovely especially if you ask to sit on the balcony. They also have great 20€ prix fixe lunch (if they are offering it in the off season).

However, if you can manage more than one of these three, by all means, go for it!