As of today I've found that Q3 is sometimes pegged at ~10% CPU in task manager, and whilst it's in this state general computer usage becomes sluggish (e.g. moving the mouse)

Killing the task seems then immediately reduces the sluggishness. Restarting Q3 then re-introduced sluggishness.
I took a dump file from task manager, let me know if this would be useful (note to self: located at C:\work\q3)
As of today I've found that Q3 is sometimes pegged at ~10% CPU in task manager, and whilst it's in this state general computer usage becomes sluggish (e.g. moving the mouse)
Killing the task seems then immediately reduces the sluggishness. Restarting Q3 then re-introduced sluggishness.
I took a dump file from task manager, let me know if this would be useful (note to self: located at C:\work\q3)