My stay wasn't that recent - I think it was about 3 1/2 years ago but I doubt much has changed since then. At the time I was either HH Gold or Silver since I lost Diamond status for a while. As a Silver/Gold I was upgraded to a corner room with a nice view - balcony on two different sides of the room. No free breakfast (so maybe I was just Silver at the time). Room was "resort generic" but comfortable enough. Pool is great and the beach at the Hilton is probably the only decent beach in Cartagena proper.
One thing I do remember and will advise is if you get a corner room ask for a higher floor since there's some sort of a grill down at that end of the hotel and the kitchen/BBQ exhausts upwards. Funny how the thing I most remember about the hotel was the grilled meat smell wafting into my room.
Overall the hotel is nice but has very little local character. It could be a resort anywhere in the world. If I were to go back to CTG I would probably skip HH points and beach and instead opt for one of the many luxurious small boutique hotels in restored colonial buildings inside the old walled city.