TOUCHPAD

Pros: Flat, smooth controls are easiest to clean. Some models have programmed settings to eliminate guesswork about time and speed.

Cons: Must often press twice--on and desired speed--to activate. On models lacking speed settings, must press up or down arrow repeatedly to reach desired speed. On programmables, small displays are hard to read.

PUSH BUTTONS

Pros: Easy to change from one speed to another with a single touch.

Cons: Hardest type of control to clean.

DIAL

Pros: Easier to clean than push buttons.

Cons: To move from low to high speed (or vice versa), must rotate dial through complete range.

SWITCH

Pros: Easier to clean than push buttons.

Cons: Limits available speeds to one or two, sometimes with a pulse option.