Take some plates and bowls with you before you make your final choice. Some dishwasher racks are flexible and can be adjusted to accommodate tall glassware or different cookware. Dishwasher capacities are given in numbers of place settings the unit can hold. Ask the dealer or salesperson for unit capacities to help you compare different models. Stainless steel and porcelain liners are very durable but also more costly.
Plastic liners are less expensive and usually last as long as the dishwasher, and are quieter.
Most families use the normal cycle most of the time, but if you must wash loads with heavy soil, you may want a pots and pans or heavy duty cycle. A covered basket is useful if you wash small items. They should stop securely when pulled out and when pushed back in. A rotary dial is used with electro-mechanical controls. You must rotate the dial to choose the cycle you want.