I've also bought 7900 xtx. and from my experience so far i would not say i'd recommend it, for Second Life atleast.
I keep having issues where my drivers time out which crashes my game, this usually happened to older games ive played such as The Sims 3 and Resident Evil revelations 2. So i had to uninstall them after trying everything i could.
As for Second Life, it gets abit confusing. at a sandbox with no objects around i can reach about 300+ fps. but in public places it can go down to 5 fps.
So i have done some tests with a friend of mine, She has a nvidia 3060. using the exact same settings and aiming the camera at the same directions. her fps stays at 30 while mine starts at 20 and slowly lowers down to 5-10 FPS (( I also have a AMD Ryzen 9 7900X CPU while hers was an older model.))