It might seem insignificant, but the springs that are used on your 3D printer can increase print quality and stability. Changing out the stock springs for a firmer spring allows you to print at higher speeds without having to worry about bed wobbling. These firm and well-compressed springs are a cheap and easy upgrade.
The replacement springs are more rigid than the stock springs, increasing consistency between prints and reducing vibration.
The replacement springs feature a flat top and bottom (vs. the stock springs' rounded top and bottom), resulting in less spring shifting during and between prints.