A classic case comparison can be seen when looking at Vietnam. They have two Metro projects running. One in Ho-Chi-Minh City (Saigon) & another in Hanoi.
The Hanoi one is Chinese built, ran into huge cost overruns, serious delays exceeding two years and had several serious accidents. This is built by China Railway Engineering Corporation.
In contrast, the metro project by the Japanese (I believe Sumitomo) in Ho Chi Minh City has been accident-free. There has been some delays but it's on track to be completed in 2021 with a much superior Japanese workmanship & advanced engineering design.