scolli01,
Welcome to Flyertalk!
The IAH Hilton Garden Inn does have a great location. Very easy access to the airport, which is why I've stayed there many times to catch a morning flight.
The hotel is clean, fairly new and such so the experience should be similar to any other HGI that you might have stayed in. Overall, a very decent property.
However, don't expect anything in terms of service. I've had several bad experiences with the front desk staff, which seemed to be less than bright and not well trained.
If you are simply looking for a decent hotel to stay the night prior to the flight I would suggest it. No frills, but good location.