Excellent for people who spend most of their time in the mixer. This feature has in fact proven itself to be a big time saver for mixers.
Folks who will have the mixer covering the screen, have a navigation window open for pure overview can now have more detail present.
What is the suggested pre- and post-positional view window ? Five seconds each way ? -edit- Harrison has a 20 second window. 10 seconds each way for track content, and 20 seconds history for live input.
Here's how this looks for Harrison console users.
If the arrangement view uses no resources, because it's not visible, then the CPU cost may not be so high with clever caching.