Sorry about being random it just happens sometimes...

I stayed a night at the HGI in April 2013 and it was by far and away my best night in a standard Hilton hotel. It really is a full service hotel from the moment you were greeted by the doorman, desk clerk, or anyone else working there. Since I booked my stay on points it was a particularly nice stay... However, it is not all that close to the airport and nothing else of interest is close unless you are into industrial equipment distribution.

Given your layover time and the minor cost differential I would stay at the HI as it is directly connected to the airport. Make certain that you book your room in dollars and then pay for it in dollars on your credit card, not pesos, and you will avoid a 19% VAT on your room!