After months of battling the spinning beach ball every time I changed a reference, I finally found the culprit, at least on my computer. I had given up on Logos4 Mac and went back to Logos4 Win on Parallels. But thought I would try one more process of elimination, and I found it.
The problem is "History." As soon as I closed the History window, Logos4 is quite snappy, comparable to Windows. Too bad because I really like the history pane, but until they get it up to speed, it is off for me.
Hope this helps some others who are having problems with slowness.
A finally happy Logos4 for Mac User.
jac