Nice sale with Aeromexico for service from Miami to Barcelona via Mexico City. This detour does add additional miles but generates some very lucrative earning opportunities.
There are some long layovers in Mexico City which would allow yo to explore the city since you can reach the Zocalo via metro, 45 minutes to an hour both ways and see the Cathedral, National Palace and Rivera Murals, and the Templo Mayor or if you have some more time you can venture out to Teotihuacán which is an ancient Mesoamerican city located 30 miles (50 km) northeast of modern-day Mexico City.
MIA-BCN would earn 21528 MQMs 5741 MQDs 3.91 MQD Ratio
Delta Diamond members would obtain 63149 RDMs, Platinum 51667 RDMs, Gold 45926 RDMs, Silver 40186 RDMs, Base 28704 RDMs
Sightseeing around Mexico City
Aeromexico Boeing 737 Business Class
Aeromexico Boeing 787-8 Business Class
Aeromexico Boeing 787-9 Business Class