I have also read that the Mi-17 is better in the “hot and high” environment than the Chinook.
After a series of Chinook crashes in Vietnam, we had a negative opinion of the Chinook and referred to it as the $*it-hook. There was also an oft repeated joke that the Chinook was the only aircraft in the world that could have a mid-air collision with its self.
Current Army Aviation spokesmen claim there is little similarity between todays Chinooks and Vietnam era models, but I'm still not convinced.