It’s the interlacing that’s the cost. Read after write forces redraw. My big win on my first AJAX app was splitting read and write into two phases to reduce a

It’s the interlacing that’s the cost. Read after write forces redraw. My big win on my first AJAX app was splitting read and write into two phases to reduce a page load from 30s on IE6 down to about 2 seconds. I didn’t even have to rearchitect. It was one loop in one (maybe 2) functions. Just had to split it into 2 loops. If React wins (which I don’t agree that it does, but don’t want to have that argument), it’s that it allows you to compose tricks like this across a whole page instead of one component type.