Look for models with adjustable baskets and flexible internal layouts for varying load requirements. For example, a tilting upper basket allows large 30cm diameter plates in the lower basket and extra flaps can be raised or lowered to cater for small items or large pans.

Not too much romance here, but essential for any functional kitchen. Buy the heaviest pans possible. Also, you should consider buying a non-stick silicon sheet: they make baking very easy!