Kim - Great catch! That location is fantastic; and the hotel does indeed look charming.
One thing to remember: When you tell your taxi driver the name of your hotel, be sure to say, "Hotel Odeon Saint-Germain, on rue Saint Suplice". This is important because there is a Hotel Odeon, just a couple of blocks away on rue de l'Odeon. The Hotel Odeon has been there many years and would be the one the taxi driver would think you meant if you were simply to say, "Hotel Odeon in Saint Germain".
I recall the dear old Odeon well, as it's the first hotel in which I stayed in Paris as a student a million years ago. It was then a no-star student hotel which we all called "The Odious". About 20 years later, on a lark, I stayed there for a couple of days to see its new incarnation as a 3-star hotel. Quite a nice change, although not to the higher standard of your Hotel Odeon Saint-Germain.
Have fun. Cheers, Fred