Bought new PC, R7 3700x, 64GB RAM, 2070 Super, new M2 drive. Performance is still bad especially using subdivision surface or undo. It’s hard to work on high detailed models.
In 2.79 modeling (with subdv) and undo was faster, but object mode with hundreds of meshes was very problematic,
in 2.81 modeling (with subdv) and undo is really slow, but there is no issue with having hundreds of complex scene and operate in object mode.
Since Blender want to be compared to softwares like Maya or 3Ds Max, I think this issue should be considered as number 1 to fix. I heard already some complaints from my friends that tried 2.81, also asking me what’s wrong 
@edit
I don’t want to be impolite. Just want to say that from professional perspective this issue keep Blender slightly in the background. If more people will notice that issue, they will bounce of from that software as fast as they wanted to test it.
I’m really happy what Blender 2.81 is right now, and looking forward very optimistic to future 
Overall, great work devs!