Agreed.
TIR is great, I used it for a couple years and loved it, but in my opinion it doesn't compare to the immersion of vr. It really does feel like I'm sitting in the cockpit. I can still have a drink and type and such with vr, just have to lift the headset a bit sometimes to see the keyboard. There are other solid vr options, the quest 2 is half the price and still good quality, though not quite as clear a view as the g2 from what I've heard. I've never tried the quest so I can't give you a good comparison.
Going by your specs you won't have any issues running a g2 and mirroring on your monitor. My rig is similar and I can't say I've noticed an FPS hit having mirroring on. I do have a lot of the in game eye candy stuff turned off, it helps in spots like flying through clouds and around fleet ack where FPS takes a hit. Worst offenders I found are post lighting and shadows.