The Hilton Dubai is small but brand new. It reminds me of the Buenos Aires Hilton in its design, a stainless steel decoration with a very modern facade and open areas. The Hilton itself is downtown and has only 2 restaurants if I recall, good and very expensive!
Dubai is small by most standards so if you are in the city for business or a short transit the Hilton is no better or worse location wise than any other hotel. If the price is high you may want to look elsewhere.

The Jumeriah beach Hilton is obviously in Jumeriah and obviously on the beach. Have never seen the hotel in person so I can't comment, but from word-of-mouth it is a very good property with average rooms but a great staff.