The big difference to me is that Red Hat family distros have been a lot better suited to managing a large fleet of servers that I want to treat as cattle, not pets. I've finally managed to get away from Debian derivatives a few years back, but here are some specific complaints I can remember from my last job, managing about 1k Ubuntu servers.

- Installing a package on RH is always non-interactive. To install packages reliably on Ubuntu, we had to set three separate "Please just install the package, don't try to ask questions" options for different layers of the stack, and still occasionally ran into buggy packages that would hang the installation waiting for a nonexistent user to type something.

- On RH, when I try to install or upgrade an RPM that's missing dependencies, it gives me an error and refuses to break my system unless I specify --force. With debian, there's no way to query "Are the dependencies for this .deb satisfied" that I could ever find, and "dpkg -i foo.deb" will instead leave it "half-installed", and your package database is broken until you manually fix it.

- I really missed an equivalent of `rpm -V` (list files in an installed RPM that have been modified since installation). Asking Google now, I see that there's `debsums` which can handle some of this; I don't recall whether I failed to find that before, or if there was some other reason I didn't use it at the time.

- On RH, automated installation with kickstart is fantastic and comprehensive. It's well-documented, and has just worked for every configuration I've thrown at it. Debian's preseed is severely under-documented, and many combinations of features are just unimplemented and silently didn't work. For example, you can reserve unallocated disk space from a raw partition, but that's ignored for LVM, so to keep space free for snapshots in my volume group, I had to configure a "delete_me" volume, and then later delete it.

- Red Hat's SELinux support is fantastic. Ubuntu's choice of apparmor and deficient SELinux support has been annoying.

- I've personally found Red Hat's packages to be higher-quality. The biggest defect I remember finding in Ubuntu's repos was a service whose init script was literally copied from Red Hat, which didn't work, as it tried to source a file of init script utility functions which doesn't exist on Ubuntu, among other issues.

- Red Hat's documentation is fantastic. Ubuntu's documentation is, uh... sometimes present.

- I've found building RPMs to be much simpler and much-better-documented than the process of building debian packages. I vaguely remember being repeatedly frustrated at debian packaging that felt like "this magic thing just interferes and does special stuff when this case is detected", vs RPM's "it just does what the spec file says to do", but I can't remember any details or examples.

- I've had a much easier time building yum repositories than building debian repositories. Just dump a bunch of RPMs in a directory, run createrepo, serve over HTTP. I failed to find something similarly-simple for apt repos.

- Red Hat family had systemd way earlier, and with way better support and integration, than Debian family. While I do agree that there are some implementation issues with systemd, it's been a huge usability and quality-of-life improvement for me professionally.

To me, Debian has always felt like it's designed for someone administering a small number of long-lived pets with a variety of special circumstances, which really isn't what I want professionally. Red Hat has felt like it's engineered for use-cases I care about.