Great experience
I stayed at the Hotel Monterrey during the second weekend of Jan 2006, during the peak season. I enjoyed my stay here immensely.
I particularly enjoyed the central location, just across from the main entrance to the old city. The 4th story balcony offered a tremendous view of much of Cartage�a. If you're looking for a large beach hotel, this isn't it, but the beach is within a $2 taxi ride.
The rooms were clean and functional, though not extravagant. The staff was very friendly and helpful. The complimentary breakfast was ample and varied. My internet reservation through a 3rd party worked perfectly.
A senstive guest might want to avoid room 401, which is next to a squeaky elevator motor. (It didn't bother me.)