I experienced the same issues. At first 3.0 worked well and I was pleased. Over the weekend, the slow down began. I do audio-only work and to remove .1 second of breath noise takes over a minute. When the program was first installed I had no issues with this. Any suggestions? I have tried uninstalling and reinstalling, but that does not help.
At this point, I would like to revert back to 2.4.x and wait 6 months or so