We wound up at the Hilton thanks to Priceline and it was a great experience. This is what I have come to expect from the better part of the Hilton Hotel family of properties. It would be perfect for business travelers but also has the comfort and convenience (to the mall) that made it great for our personal getaway.
Like the other "nicer" Hiltons I've stayed at the design of this one is decidedly modern, some would say austere if you go by the lobby. I think that's why it does not immediately strike you as a 4-star hotel as others have noted. It lacks the warmth and/or classic feel of other luxdury hotels, but it has all the services and ammenities. Go to the Fairmont or Ritz for your romantic weekend (but expect to pay more).
The rooms are well appointed, in great condition and are very comfortable. The free bottles of water are always welcome (as opposed to those with the $6.00 neck tag) as were the chocolates and turn down service. We also had a chance to visit the 14th floor lounge. And while the breakfast was very short on protein (i.e it would kill an Atkins person!) it was fine for getting your day going, clean, well layed out, and well managed.
Having stayed at the nearby JW Mariott and Omni hotels I would put this on a par with those (though again the JW probably is a warmer feelling hotel). And if you need to be in the Galleria area, it's a great choice.