“They work. They study and they will give back more than they get from the US.”
This has been my experience with my Chinese-born friends, now al proud American citizens. Doesn’t mean some shouldn’t be closely watched though.
China does use the students it sends as an information resource, farming out requests for small amounts of information to thousands. It is harder to track by counter-intelligence authorities here, but it gives the Chinese a far bigger picture and more information overall here. It is everything from “get info on the advancements at the defense affiliated projects at your college” to “build up a bio on person XYZ” to “go to this machine and click this link, let it run”.