I have been flying in VR for years, since the release of the first commercial Oculus headset (Rift CV1) and FlyInside (a tool we used before P3D/XP got native VR support). My current setup is:
Ryzen 9 3900X running in "Game mode", ie. no hyperthreading, half of the cores disabled so the remaining six cores can run at higher core speeds
X570 board with 32 GB DDR4-3200
GTX 1080ti, because I can't afford to compete with cryptominers: in my part of the world, an RTX 3090 sets you back more than 3000 EUR (more than 3800 USD),
if you can find one; while a 3080 -- a card that launched with an MSRP of $700, iirc -- is about 2000 EUR, what a bargain!
Valve Index throttled to 22.5 fps, because my brain is used to low frame rates by now; thanks to reprojection, head rotation is smooth, but head movement suffers from the low frame rate; higher framerates are possible, but I need my eyecandy, I don't like to constantly adjust settings based on where I'm flying (e.g. city vs bush), and I don't like the stutter resulting from fluctuating frame rates, so I fix the frame rate at the highest value my system can sustain; some people fly at 18 fps
Generic advice:
even with the latest generation headsets, the resolution used to fill a decent monitor is blown up so it fills your entire field of view; the compromise is to allow the picture to be blurry and limit the field of view (like wearing blinders); while this is accounted for in "experiences" and games made specifically for VR, it definitely needs getting used to when flight simming
once you've had your first satisfying experience in VR, you can never go back to enjoying a flight on flat monitor; you can fly flat, but you'll always have that nagging voice in the back of your head, telling you that you could sit inside the cockpit instead of just in front of it
If you're excited about flying in VR, by all means, do it, what are you waiting for? If you're excited, you won't mind overcoming hurdles like "growing your VR legs" in made-for-VR experiences and games you can play at 90 or 120 Hz until your brain lets you stay in a cockpit in MFS (potentially at much lower framerates) for an extended period of time without giving you motion sickness.
If you're hesitant, maybe wait for the next headset generation, or the one after that. It will get better, so much seems certain.
