Spent three nights at the Art Hotel in November 2009. Nice, smallish rooms and neatly appointed. Breakfast OK with no Decaf coffee available. Guests are mostly from Europe and Canada (no Argentines) and front desk very accommodating. Restaurants nearby are neighborhood eateries where you'll see nothing but Argentines!
Two blocks from Calle Santa Fe -- lots of shopping, very large book store with a few English soft covers, etc., and on the edge of the Recoleta neighborhood. Not far from Calle Callao where the shops, eateries, etc., get better the closer you get to the Alvear Palace.
Very good quality for the money.