I loved the Westin Excelsior in Rome. Going back for another five nights in September.
I did not like the Sheraton Park Towers in London. I found it to be cold, impersonal and over-rated.
Instead, I much prefer the Sheraton Park Lane, recognizing many others have a different opinion. All I can say is I have never had a bad experience, most of them quite delightful in fact.
I am eager to try the properties in Spain and Austria some day. I generally prefer older, traditional, formal properties.
Cheers,