Operating system: macOS Mojave 10.14.2
Graphics card: Radeon Pro 560X 4096 MB
Intel UHD Graphics 630 1536 MB
2.80, 1b839e85e142, blender2.8, 2019-04-25
Download file is blender-2.80-1b839e85e142-OSX-10.9-x86_64
Short description of error
It takes 2 seconds to select or deselect vertices, edges or faces in Edit Mode. It makes it almost impossible to edit the model...
The model is not very complex, at 200k vertices.
Exact steps for others to reproduce the error
Based on the default startup or an attached .blend file (as simple as possible).
Enter Edit Mode and try to make changes to the model.