This exact question has been asked before. You can do a search in this forum -- I replied before too.
I stayed there two years ago. It's not too far (but not too close) from the Metro -- ten minutes. It's a newer hotel. It's pretty generic -- if you are used to US courtyard's its the same with just a smaller (30-40% smaller) room. I apparently didn't get a suite
I walked to the Arch the first night I was there. It's a long walk but definitely doable.. just tough to walk up to the top of the Arch after all that !
If I wanted to stay in Paris on my own dime I'd stay there again. Next time I go I'm going to blow the points for the Marriott.. that's quite a location. But I ain't paying the $200+/night or so for the hotel.