General view is the Ritz-Carlton is the best in town - I certainly wasn't disappointed when I stayed there in May.

The Adlon is a joke. It is a tourist attraction in its own right, so the lobby and bar are overrun day and night. The furnishings, at least in the public areas, are starting to age now as well.

I am led to believe that the Regent still has the old Four Seasons furnishings etc, but that all the good staff left (mainly for other FS properties) when FS let it go.

But if you staying for a week, why not switch hotels and experience a couple of different areas? Eating the same buffet breakfast for a week is not fun in my experience. The R-C and Grand Hyatt are virtually adjacent so you could switch between those easily.