The main utility of the .rar file is its significantly smaller footprint compared to the original Steam or GOG installation.
Repacks sometimes change the default save path. Check the settings.ini or the appdata folder if you need to back up your progress. Punch.A.Bunch.REPACK-KaOs.rar
KaOs repacks generally aim for 100% losslessness, meaning no game files are removed or downgraded in quality (unless specified). The main utility of the
A "useful paper" for this type of file should include a section on best practices: Punch.A.Bunch.REPACK-KaOs.rar