For short columnar edits, it's not really perceptible, but if you make columnar selection of a mere 1500 lines or so, you'd notice a very noticeable lag. Now some of this could easily be that I do almost all of my work on a G4 500 powerbook. But it's still VERY slow.
Now, more seriously, I know that my selection length was rather extreme. But it took about 5 minutes or more for TextMate to catch up when I had typed in the 4 characters I'd wanted to replace ('None' It was python).
-- Robert M. Zigweid http://robert.zigweid.net rzigweid@zigweid.net