that's what I figured do you drive your car at full speed everywhere? do you run as fast as you can while using a push mower? the answer to both of these questions should be no. that speed is there to get you between the spots/angles you can cut at, nothing else. there are things you can do to let you cut faster, as mentioned, getting better blades with a mulch kit will let you process more of the clippings instead of just piling them up along side of you. yes, going slower lets the blades have more time to process the grass. in order to be able to mow faster, you would need a mower with a faster blade speed and/or better deck setup.