I have 14 files open in three tab groups. The main window has the class window and two tab groups, with a third window floated to a different screen with another tab group. CPU usage remains a steady 33-34% whilst SlickEdit is idle.
I'm posting this because that seems to be right at (or just past) SlickEdit's limit for open windows/files on my Mac. I'm running Macbook Pro Retina 15, 2.8GHz, 16GB RAM, Mountain Lion 10.8.4, SSD internal drive.
At this point I do see slow response, a very few missed keystrokes, and often difficulty registering triple-click to select a line.
However, as I click back and forth between tab sets to count the above, SlickEdit CPU usage has dropped to 1-2%. Now that it's idle while I continue typing in the browser, it's climbed back up to 20%.
So... there is something chewing up CPU, but it doesn't seem to be the continuous-repaint problem. SlickEdit 2012 on Mac is unusable (continuous repaint), and B6 is not only very usable but, for me, far superior to anything else because I can spread across multiple screens.