I used the national carrier Avianca several times and found them very safe, good service and quality, and very reasonably priced.
The beds at the Art Hotel were comfortable and the thread count on the sheets just made it to the acceptable level. They were nice big twin beds.
The breakfast and bar staff were lovely. The front desk was helpful but I was a bit shocked when I was told that they had run out of maps.
Breakfast was a buffet. I highly recommend the beans. There was also a sort of pancake-shaped local bread. The lovely waitress showed me what to do with this.
Overall the highlights of the Art Hotel Medellin are the fantastic 6th-floor area, the art design, and the brilliant location.