I am going to start by saying that I do not recommend opensuse leap currently.
It is pretty fucking old, and opensuse should be doing a major release in the next couple months.
So I am going to talk specifically about tumbleweed.
Yes, tumbleweed is a TESTED, well supported, and well documented rolling release. Unlike manjaro where they simply hold packages back in order to improve stability, they literally run each and every package before shipping it.
One of the major features of opensuse in general that I really like is that the main opensuse repo has a crap ton of software. I generally do not like to add extra repos to an OS I use on a daily basis, so the fact that I really only have to install the packman repo for video codecs, and the games repo for things like playonlinux really helps to prevent opensuse from turning into a frakenstein OS that breaks every time you update.
I know this topic has been beaten to death, but you do get yast. Yast is a very cool tool that lets you manage anything from disk partitions, to setting up KVM, to managing kernel settings. Its extremely powerful and will probably be your best friend.
The last two bits I want to cover are OBS and Zypper. These two topics are the defining line between opensuse and fedora.
Zypper is your friend. Zypper is your life. Zypper is your savior. Enough said.
OBS stands for Open build service. The open build service is kind of like a studio where you can try to compile software for opensuse. You can see what did not build, and get advice and physical help from the community to try and get your piece of software built for opensuse. From there they even help you package a repo, and help you maintain said repo.
So right now, elementary OS's pantheon desktop does not work on opensuse or fedora. IDK where fedora stands on the pantheon desktop. But for opensuse.......
I can see where the project stands, how I can contribute, and it will even give me updates when progress has been made.
The OBS system is what has contributed to a large software base for opensuse. Its almost like a stable and well maintained version of the AUR.
So to wrap this up, you get a great distro that is more up to date than fedora, probably just as stable, you get a great package manager, great tools that fedora doesn't have, and a much bigger software library.
What is not to love exactly?