It won't rust or develop rough edges to snag clothes. Another good option is porcelain with a double plastic coating. Avoid drums that are made entirely of plastic as they aren't particularly durable. And non-enameled porcelain will rust. Check for fit and reach.
Most dryers have doors that swing open.
Make sure the swing direction fits your space and allows you easy access or can be switched to fit your needs. It's a real bummer to lean over a door and reach in when the door opens the wrong way. Some models have flip-down doors that are good to pile clothes on and will fit under counters. Determine if you need a rack. If you have lots of sweaters or sneakers to dry, consider a model with an attachable drying rack.