Well, compared to the Meurice or Plaza the Louvre is obviously just "up-scale". Good enough for me.

I like it for the reasons Nicolas mentioned. The black and red decor is nice. When I went there they frequently had a piano player or some jazz playing, too. Don't know if they still have that.
The location is also very convenient because it is so central, close to metro, bus and taxi. Nice cigar shop next door, too.
I do like the Marly also. Is outside smoking still ok? I'd think so.
Till