I was at the Sheraton a month ago on an award stay, and I liked it fine. They upgraded me to a nice, big room. The front desk was friendly and helpful. It's a short walk to city center, a somewhat longer walk to the old town. There's a park a block away, and a little shop where you can buy food and drink just across the street. There are restaurants within walking distance, but I didn't try them. I haven't tried the Westin.
Have fun in Warszawa.
[This message has been edited by PaulMSN (edited Mar 14, 2004).]