Love the plugin, exactly what I was looking for. I now have around 70 sidebars, and I expect that eventually I will go well over 100.
The problem is that the sidebars respond VERY slow. When I add a new one it takes about 30 seconds to complete. Then when I add for example the text widget and click in the title textfield to type something, it takes about 1 minute before the widget responds.
When I had less sidebars this problem didn’t occur. I also read in this forum that other people also have a lot of sidebars and they don’t seem to have this problem.