Visually impaired or not, full desktop zooming is always a great feature to have, and the Compiz plugin that allows you to do that had always been one of my favorites.
A couple of years ago, when I first tried it, I was impressed by its speed and smoothness, especially on my then 7-year old machine. Sadly, for I think two Ubuntu releases, it became really choppy which badly affected the overall experience. Since then, from time to time, I found myself tinkering with all kinds of settings, but I never got to the bottom of it. It was especially frustrating, as this was happening on a modern computer, with powerful specs.
But finally, just yesterday, while browsing the Ubuntu forums, I came across the solution: go to your Preferences menu, open up CompizConfig Settings Manager and look for "Mouse Position Polling". Inside it, decrease the interval to any value under 10. Done!
This should also be a lesson for all of us to always dig deeper and search under the surface. If I had been curious to learn about every plugin in CCSM, I would've found this solution much earlier. How? The Compiz Wiki page provides this description for the Mousepoll plugin: "How often to poll the mouse position, in milliseconds. Reduce this to reduce choppy behaviour." Well, I'll be damned...