From 2x2s to 4x4s - heat map to visualize trade-offs

Not a grand presentation design insight today, but a quick sketch.
Matrices such as 2x2s are often over-used. When you combine them with a heatmap, some colors and some gradients, you get a nice visualization of a trade-off:
Update: to show that the big lines are not grid lines, here are the 3x3, 2x2 and 1x1 versions of the same chart: