Performance refers to frame rate and stutters.
Please indicate your playability of the sim with the following statement - VR performance (frames per second) in this build is generally:
- Great
- Good
- Acceptable
- Poor
To report a bug, please use a sub-category of Sim Update 4.
Please provide additional information in the comment section below 
Reminder:
- Add-ons/Mods/Community content are not official Microsoft Flight Simulator products and may cause issues with the Build. If you encounter any issues, move ALL add-ons from the Community Folder to another temporary folder (on the desktop for instance) then try again. If the issue stops, add back the community content one by one until you find the add-on that is causing the issue.
- We strongly advise not using the Dev-mode mode if you are not a developer/content creator
Lots of stutters in VR, specially during approach and landing. It gets worse when looking to the left and right. The first versions were much smoother.
This version definitely has reduced performance vs. .19.
Overall FPS seem fair, but the smoothness of frame timing from .18 and .19 has gone away.
Since .19 and .21 my performance stays same but the smoothnes is gone indeed. Lots of stutters coming from huge long frames (up to 3 seconds, but mostly between 0.5 and 1 second AND at least this happens every 5 to 10 seconds), also more CTD and even WASM Crashes in PMDG, wich I never had before in any of the SU4 Betas. .19 was smoother compared to.21. This .21 build is no joy in VR, it is so bad, that I am back to MSFS2020. Because SU3 has a Mainthrread issue in its released build, wich is a real issue for lots of us.