Join Date: Aug 2011
Location: Barcelona, London, on a plane
Programs: IB+ Gold, TK E+, Hyatt Globalist, Marriott LTP, IHG Diamond
Posts: 14,184
I've been upgraded to suites at both properties.
There is a lounge at the Hilton. No lounge at the Conrad. Breakfast is in the restaurant at both hotels.
You aren't in Cartagena for the beach. You might be there for some sightseeing, in which case the Hilton is much better located. If you have no intention of leaving the hotel property, the Conrad is newer and has a much nicer pool IMO.