Known for being consistent in maintaining a highly secure system. Several other popular distros use Debian as a base or core for their own Linux OS, the security being one of the main factors why it's so commonly used.
Non-free hardware will not work upon install of Debian and the user will need to search out the correct non-free software to install in order to make them work. This can be difficult if one of the things not working is the WiFi connection.
Fedora does not support proprietary drivers, meaning that users may have problems with a lot of hardware when using Fedora. The software to make that kind of hardware work can be installed, but it can be done only through third-parties and it's not easy for the average user.
RHEL favours stability over being up-to date. For this reason it ships with packages that may be up to two years behind in order to ensure stability over everything else. Using older versions for packages means that they have been thoroughly tested and used in production for quite some time, and...