I don't know if it is directly related to the update to 6.01, but now I'm experiencing an extreme lag using the brush tool.
Used this brush millions of times, had some lag issues while (shift-N) having survey opened on the second monitor.
Now the lag is very evident. Sometimes taking 5 seconds to see the changes I brushed. If I did multiple brushes, sometimes the pen stays down (from the cache) while jumping to another brush start point, placing an unwanted brushstroke between the end and new start point.
The lag worsened if I have the second monitor in use (shift-N)
Restarting LR CC doesn't solve the problem. Rebooting the PC solves it for a short while.
Windows 7 64. 16 GB LR CC 6.01
Try a test.
Edit >> Preferences >> Performance
Then disable GPU acceleration.
For Windows you should go to the website of the manufacturer of your graphics processor and check for driver updates. After updating you could try switching GPU acceleration on again, otherwise leave it disabled.
It worked immediately.
Now I ask myself; "Why do I own an expensive CUDA capable Nvidia graphics card with dual head and load of memory?"
I really want to use the LR CC GPU option.
And yes, the driver software was updated last week, I'm not going to do an upgrade every week/time I get an Nvidia message.
AFAIK the GPU is not meant to affect the brush tools, only the sliders, but it was worth the test.