Who was better?
Although the Romans built hundreds of miles more aqueducts than the Aztecs, I have to say, I think that the Aztec aqueducts were much more sophisticated than the Roman ones, and were much more efficient. That is partly why the Aztecs only had one or two aqueducts, and the Romans had almost fifteen. The Romans aqueducts were simple, and were not healthy enough to keep away plague and disease. The Aztecs were way higher than the Romans in their level of engineering. They could control where their water went, and where it came from. They could even control how fast it went(http://www.history.com/topics/aztecs/videos/aztec-aqueducts,Oct 12, 2014). So, overall, I think the Aztec had much better aqueducts than the Romans.