Hey Alex, As mentioned -- I did try that (using the code from your blog), even using a labelFunction instead of dynamically detecting the on/off: it was still about the same speed. The performance hit is somewhere else deep inside DataGrid. I've spent many hours researching performance of my DataGrid as a whole, but at the end of the day I don't know enough of Flex internals to debug it. Just seems no one has really tried to stretch DataGrid as far as I wanted it to go :)
I did have luck with my alternate method... I've just moved the scroll bar to the left, and now I'm scrolling the container itself. It might be a nice feature to think about for future versions of Flex to toggle scrolling to dynamically generating renderers vs scrolling a clipped area. -Kyle
