On a three night trip with three different Hotels so I am staying at three different bands (not on purpose - it just worked out that way). First night was at a Westin (my first Starwood property). Very comparable to a Marriott but they did not have a CL. Was given a breakfast coupon instead for a hot buffet breakfast. Nothing special beyond the usual CL fair. Room was comfortable, clean, and modern. Staff was very nice.
Next was a Sheraton (my second Starwood property). Based on this stay, I think that brand is in trouble. Is it supposed to be comparable to a full service Marriott? I hope not. It was very dated with worn and ripped furniture both in the room and the common areas. The lounge was also a bit below standard. After looking it over, I passed on the evening food offering. The location was also oddly placed without good markings so that it was difficult to find (other guests also had that issue). Some of the treadmills and ellipticals in the workout room were not working. My room looked like a second tier hotel room with the bathroom being split and the HVAC unit not being integrated into the walls. Staff was pleasant but overall I hope this isn't typical of all Sheratons.
Finally was the Marriott Gateway in Crystal City. This is one of my favorite business hotels and was the clear winner this trip. They upgraded me to a suite. The workout area is great which is good because this hotel has a great breakfast in the CL to put all of the calories back on. Along with the usual items, the CL breakfast includes smoked salmon and a staffed omelet bar.
So after dipping my toe in the Starwood ocean, Marriott still came out the clear winner. Your mileage may vary.