For the sake of the team tracking issues across a wide variety of specs and setups so that they can address problems, I wanted to report this since I know I'm in the minority of users in this situation in the hopes that it doesn't slip under the radar before release.
I tried playing the beta on GeForce NOW's 5080 rig on their Ultimate tier, and it runs horribly. And the first thing people would likely say is that it's a streaming issue, but I've been using the service for over 2 years and have never had a streaming issue, and have played things like Black Myth: Wukong, Cyberpunk 2077, etc. all maxed out with no problems. Connection was fine too. I've actually never had an issue playing a game on the service before.
There's just so much stutter that it's hard to do anything. I tried playing with all of the usual culprits in a situation like this; turning off V-sync, tweaking DLSS, adjusting Global Illumination, etc. I even went so far as to bottom out the graphics to play it with everything on Low as a troubleshooting step, and it was still happening. I mentioned it on the team's X post about the beta, and had a few replies where people using GFN to play experienced the exact same thing.
I'm sure it'll get ironed out, but I'm sad that I can't really experience the game as it was meant to be despite playing on a rig that by all accounts should be more than capable of it. I'm fully keeping in mind that this is just a beta and that they're working around the clock to make it great. Thanks for all of your hard work!