No home is complete without a good stool! But metal step tools are indeed preferable. Not only do they provide a handy seat at the counter, they give you that extra few inches of height you need to reach that top shelf of your cupboard or to prune the dead leaves from your hanging plant. These stools really are indispensable.
The style where the seat tilts back to reveal the steps I reckon is the best one to purchase. Another valuable feature to look for when you are shopping is the kind that has arm rests. The arm rests make handy places to grab to catch your balance when you are using the stool as a miniature ladder.