Performance wise? They're more or less the same with the rx 5600 xt on new bios with a slight lead in like 3% but really it depend on the games.
Cooling wise? This depends on the brand and design of the card rather than the chip. If you buy a cheap rtx 2060 then it'll run hotter and louder than a rx 5600 xt. Same goes for rx 5600 xt.
Now, the real deal breaker is the driver. Amd gpus are known for their drivers issues. You will get a bunch of people saying their rx 5600 xt or rx 5700 xt works fine and another bunch saying they have a lot of issues. You'll need to do research before downloading a driver update. Well this is really just going on youtube to watch the review of latest drivers. It's not all bad with amd gpus because they...