If you search here I know I and others wrote plenty of info on these hotels. The Sheraton Jumeira Beach is a nice resort beach hotel, far away from town. The Creek property is a very nice city hotel. The Sheraton Deira is nearby the Creek and still a decent city hotel. However if it was my money and I was renting a car anyway AND I liked swimming in the Gulf (which I do), I'd go ahead and hit the Beach.
I'm not sure what is going on in September in DXB? The rates are much higher than I would have expected given the 45 degree weather.