The Index is a great headset overall and is working fine with FS2020 as long as you take care of some low level details.
This should get you started and with the 2080TI you’ll have ample room to expand from there:
My 2070 SUPER VR settings and suggestions (Index - SteamVR)
Besides, even if the Index has a 1440x1600 panel “only” (compared to 2160x2160 of the G2), I’ve been also trying pushing the Index far beyond my test system video card and I must admit at 200% SteamVR SS*, it was nearly allowing me reading EFIS screens as easily as with the G2. The advantage with the G2 is that I can do it without much SS and with my current test system hardware. With a 2080TI you really should explore pushing the Index in this direction, it is stellar. (it is starting to be close to the G2 at 150% - yes you can do the maths and see it is close to G2 but the reason has more to do with Nyquist in my opinion that just pure resolution, hence 150%).
There are key differences between the Index and the G2 beyond panel resolution which makes it hard to choose one. I personally prefer the Index offering as a whole, because it is really a solid piece of headset compared to the G2 (plastic, straps, etc…), it is more immersive thanks to the wider FOV, it has eye relief adjustment which helps depending on your vision, it has lots of controls (luma, RGB, refresh rates etc…). Also in flying a lot lately with the G2 and the Index, I realize what is probably better with the Index is not just the FOV but the vertical FOV, especially with aircraft. I find it more immersive because you are literally viewing from toes to head in one go. Tracking is unsurpassed in precision, stability and reactivity (lighthouse vs inside-out - it really is so evident when having the 2 to compare). And once you try the Knuckles and see how this feels natural using them…
The ideal headset to me would be the Index with the G2 panels and the Pimax Artisan horizontal FOV. It will have a pixel density between the Index and the G2 and all what makes the Index probably the bet overall headset for VR on the market today still.
*I don’t remember if I was using FS2020 or SteamVR SS for this one, I’ll let you try out!