I have tried both Armbian 23.02 and Ubuntu variant from the Orange Pi on Geekbench 5.5.1 and 6.0.0 preview. The Ubuntu variant from Orange Pi has a better benchmark than the Armbian.
I advise that you do it the other way round: take a look at the download sections for stable distributions and buy one of those boards. A stable version of Armbian for the Orange Pi 5 might take months, years or never appear at all. All work here is done by voluntaries in their spare time, so don't expect anything, except you might have to learn how to do it yourself.
If you want something stable now, it might be worth taking a look at the official Orange Pi 5 software releases. I tested their Debian image and it worked so far, even transfer to and booting from NVMe. Didn't test graphics acceleration, though.
