I think the Pen is nice but the real draw for me is the bookable "shuttles" using the house Lexii and Rolls Royce Phantom to shuttle you around in style. The rooms are comfortable and the service decent. The Deluxe and Grand Deluxe rooms have cheapo Zenith LCD screens which is quite disappointing.
The Beverly Wilshire was disappointing when I stayed last summer but it shouldn't be long before Four Seasons has this property up to par. The FS Beverly Hills is very nice -- reminds me of a Dorchester Group hotel in ambiance and decor but with better service.
I find the service at the Pen and FS to be about the same but I found F&B to be far superior at the FS.