AMD on Linux is pretty much hassle free

AMD GPUs are fantastic on Linux. I'm running an MSI 6800XT and the only flaw is the the RGB lighting isn't properly exposed so I can't turn it off. Everything else just works and I've never had to give it a single thought since buying it. I just put it in and started playing my games.

Generally speaking amd is favored over nvidia on linux because it's driver lives in the kernel (more free), better wayland support (this is changing tho) and not having to install a driver manually or an installing a restricted driver from the package manager. I've been running my 6900xt for a couple of year and it's been great. The only downside of amd is if you need/want some of the nvidia tech like rtx and cuda. Here are some older benchmarks from when the 7900 xt was coming out https://www.phoronix.com/review/rx7900xt-rx7900xtx-linux

It's been working flawlessly for me. Brand new cards can be a little bit buggy at the beginning as they release before the drivers are quite ready, but my Vega 64 and RX 570 have been absolutely flawless the last 4-5 years. AMD's fine wine reputation is especially true on Linux.

I've always had issues with NVIDIA's drivers and basically never with AMD. I can't recall when is the last time I had driver-related graphical issues, but I sure can with NVIDIA. The only time I've had issues with my AMD cards is when I bought the Vega 64 at launch and had to run a dev branch kernel and mesa for it to work properly, but once that made its way to mainline and release kernels I haven't had to do that since.

Any AMD gpu works out of the box on any linux distro...

I haven’t seen too many positives regarding Radeon on Linux

Funny you say that, because Linux users have a lot of hate for Nvidia due to its poor support and closed-source drivers, and lots of love for AMD with it's great support and open source drivers.

AMD GPU's are literally plug-and-play in Linux.

I am on Rx 6700 XT with Ubuntu and it works flawlessly

I'll suggest you tu use a PPA to get the latest Mesa like kisak-mesa

For how great AMD usually is on Linux, it's not without it's issues. RDNA2 (the entire RX 6000 series) still suffers to this day from this 2 years old issue that can cause stutter in games as the GPU constantly downclocks itself aggressively. I still prefer it over Nvidia (having owned one and now using AMD) but just be aware, it's not all as perfect as some Linux users would have you believe.

I have an RX 6800 (before I had a GTX 1080) and Linux works pretty well with AMD. You don't even need proprietary drivers.

I only installed 1 proprietary library to enable ROCM but keeping the stock amd kernel GPU driver.

I haven't had any issues with my 7900 XTX since I updated mesa to 23.1. If Ubuntu has that available you should be good to go.

One warning, if you use a display over HDMI, then you might have a bad time with Radeon on Linux. I use an LG C2 TV as my monitor, and there is a bug in the driver that forces it to a crappy ycbcr mode that ruins text clarity. I did try all manner of workarounds like hacking up the EDID profile, but I gave up and went back to Windows for now.

It's a very specific issue, but a showstopper if it affects you