if you want the beach stay at the Sheraton Jumeirah beach resort. in addition to the beach the hotel is located at "the walk", a trendy spot in Dubai marina. lots of restaurants and shopping stores. very crowded at night.
if you don't care about the beach, then sheraton Dubai mall of the Emirates is a better option. this hotel is connected to Mall of the Emirates. a huge elegant mall. also the mall is connected to Dubai metro. you can use the metro to visit other attractions. I personally haven't used the metro yet as I always rent a car but I heard its fast clean and very efficient.
of course the Grosvenor House is the best option. ask the hotel if they can do cash&points for your stay. some times it works.
book your hotel today as staring from tomorrow ( March 5 ) cash and points rate will go up. if you are undecided book both now. you can always cancel the the you no longer want.
enjoy Dubai.