Some info:

Hanoi - Vietnam capital city.
Population: 6.448.837
+GDP per capita: 3600 USD (2015)
6800 USD (2020 estimate.)
+Skyline ranking: world - 52nd (emporis.com)
world -51st (http://tudl0867.home.xs4all.nl/skylin...)
+Tallest building: Hanoi Keangnam Landmark Tower 336 meters.


Saigon A.K.A Ho Chi Minh City
+Population: 7.981.900
+GDP per capita: 5131 USD (2014)
5538 USD (2015)
9800 USD (2020 estimate)
+Skyline ranking: world 81st (emporis)
world 63rd (http://tudl0867.home.xs4all.nl/skylin...)
+Tallest building: Bitexco Financial Tower 262 meters

Source:
http://news.zing.vn/Ong-Huynh-Van-Nen...
http://news.zing.vn/Thu-nhap-binh-qua...
http://www.bvsc.com.vn/News/2015115/3...