The 1000xm5 headphones are far better in terms of noise canceling for sure. Comfort is excellent and good for travel or getting away from the world. I'd also give them a more neutral sound vs Project Rock has more of a bass centric approach depending on you EQ settings. Also, you should consider the project rock has an ip4 rating and you can remove/wash the ear cups. For my money, I'd get them for the gym for sure.
@lyndonmacaraig6108 Yup, that would be my concern. They're excellent headphones past that though. I'd just be concerned with not being able to wash them or having them get damaged