I answered on the other thread but I'll add here too. I've stayed here a number of times and really like it. The view rooms of Les Invalides are stunning. That gold dome when it's lit at night is beautiful. I first stayed here on the Paris and Heart of France tour, but then have stayed several times on my own.
The only minus is that the breakfast room is small. If the tables are full in the breakfast area, you can get your food and take it out into the lobby/lounge to eat if you don't mind your food being on a low table.
Staff there is very nice, it has AC and an elevator. It's between 2 Metro stops but they are both on Line 8 so it doesn't matter which way you go. To me it's very walkable to the major sites BUT I like to walk a lot in Paris. You'd think since it's on a busy street that it might be noisy but I've not found it so.
I'd book there again with no problem.