I'm against the need to use GMO seeds in order to achieve yields large enough to feed the entire world.
Countries like Argentina, Brasil, Canada, and USA shouldn't be exporting as much food as they do to other countries. Other countries need to be self-sustaining.
They also encourage poor farming practices. For example, Round-up ready crops mean that farmers can just spray more Round-up on their crops. Another example, modified soybeans are designed to grow in dried up land, so they can keep cutting more Amazon forest and plant more soybeans once the soil dries up (which is what happens once the lush canopy is gone).
So, yeah, I'm a little against.