Well, I now had the experience with all three, and in my opinion, the order of feel are in descendent order: MS2020 and P3Dv4.5 then XP11.51 (Vulkan).  Ignore the flight model with the planes in MSFS2020, the visual with MSFS2020 is very good in my view.  P3D v4.5 also performs well, although the graphics is dated with land class based sceneries.  With XP11, the effect looks blurry and looking down at the ground from 1000-2000FT I have the feeling like I am looking at a magnified glass with the roads looked much larger than real life.  In 2D, XP11 with Photoscenery is comparable to MSFS 2020 but in VR, it feels a bit strange.  Obviously, this is just my observation and I don't have any scientific measurement to back them up, but just by comparing the way each sim implements VR, I must say I prefer MSFS2020, despite its many still shortcomings. Thoughts?  I would love to know your actual experience.

P.S. I am using the Quest 2 via Oculus Link, flying over the same location and with no weather, clear sky in all three sim.  I used the xCub in MS2020, A2A Cub in P3Dv4.5 and the SMS Beaver in XP11.  The idea is to use planes that are using the least system resources, with similar cockpit view as I looked out the Windows. In all three, I did short flight at my home Airport: CYOW.  MSFS2020: default scenery, P3Dv4.5: ORBX Global, XP11: Ortho4XP Photo scenery.

Never tried X-plane, but I think that P3D performs better than MSFS in VR, at least on my system. Also, V5 of P3D is significantly better in almost every sense than 4.5. Better sky and lighting with EA, better night environment, better performance.

If you fly tubeliners I'd say P3D is vastly superior. Who cares about ground scenery at 35000 feet? For GA VFR sightseeing, MSFS is superior.

I feel the same way though I use P3D5.1hf1

The scenery in MSFS2020 is truly amazing-everywhere!

Innumerable developers continually producing new stuff to fly-planes,airstrips,flight plans etc

P3Dv5 stuffed my Milviz planes too-bulk of them not available 

My P3Dv5 and X-Plane lie very quiet and unused

if I do go back for an occasional flight I am reminded how great MSFS2020 is

Really tough times  for the competition and I do feel for all the developers left high and dry by this quantum leap in simming

xxd09