I'm writing this from the Westin in beautiful downtown St. Louis. I have a king non-smoking room - and I'm impressed with the size of the normal room (nice entrance hallway with bathroom and 2 closets). If you're down for a Cardinals game - the location is perfect. If you're going to the Saavis Center - you probably want the Sheraton.
One other thing - when I booked the reservation - the e-mail confirmation noted that I could upgrade to a Club level room for only $30 more.
So far, it's a great hotel.