The Jardin de L'Odeon is on 7 rue Casimir Delavigne -- different from Hotel de L'odeon. Jardin de L'Odeon has a higher travelocity rating for what that's worth -- the hotels look comparable to me, even in terms of location. I'd do whatever is cheaper (actually I'd get an apartment but you've heard my verdict on this... there are some really cute apts that people have rented for around 100E).