This is really cool, Ubuntu is now releasing native distributions that can be run directly on the Raspberry Pi. No longer do you need to use specialized Raspbian distribution.
These releases are certified by Canonical and will be as stable as other architectures.
The release is Ubuntu 20.04 LTS and is available here
The main advantage of using Ubuntu 20.04 LTS over Raspbian is 64 Bit Support and complete and updated distribution.
I haven't seen or performed any performance benchmarks, but I am sure they will come soon. I suspect performance will be really good.
It is pretty impressive support for as far back as the Raspberry Pi 2 is available (although only in 32 bit).
Installation is as simple as copying the Ubuntu image to an SD Card and booting up. With the Raspberry Pi 3 you can actually boot off USB Flash and USB Hard Drives, so I assume you can install that way as well and will likely yield much better performance.
These images are Ubuntu Server edition and not a workstation, so if you want to run a UI you will need to install a desktop. This can be done as simply as:
sudo apt-get install xubuntu-desktop
sudo apt-get install lubuntu-desktop
sudo apt-get install kubuntu-desktop
Just pick one you prefer or try them all.
With the Raspberry Pi 4 performing as much as 100% faster than the Pi 3 there are tons of potential.