I also looked both cards and decided to go with the 7900 XT…after few days it looks like I made a wrong choice 
No doubt, it is a very strong card…when it works. It took a few CTD to figure it out the Radeon driver is crashing when MSFS runs in DX11 and opening Navigraph Chart in browser. Many user reporting this issue. Obvious choice would be to run in DX12, but then the scenery is messed up with add-on airports…sadly, but thinking to change it to a 4070ti. Will miss the 20Gb VRAM, but in this case less is more (being able to do a flight without CTD)