I would choose the Westin every time. the rooms are light and modern and NEW!!
the bathrooms are georgeous and the exec floor is large and airy and the food is great and the staff most pleasant.
I have only stayed in the new section but there is a historic old section which used to be the Post Office.
I have a friend who stayed there and did not like it at all and I have had a real problem convincing him to go back to the Westin.