I usually need Small sized bike frames as I'm vertically challenged, being just 5'6". I also have short legs so struggle with standover height. As an example, I have a 52cm Roubaix SL4 road bike but I struggle to plant my feet flat on the ground whilst standing over the top tube. The same is true of my hybrid. Both are effectively small frames. In all other respects, the bikes feel comfortable to ride.

So, how important is standover height?