Steel Cabinets
The house I own had Lyon steel cabinets from the time of construction in 1952, until I tore out the kitchen for the major (and ongoing) renovation of the house.
Hans is correct that they have more storage space - about 1.5" more than the same width wood unit. Denting is not usually a concern in a normal kitchen environment, and if it happens, can be repaired the same as an automobile panel. Paint around the pulls can wear off eventually, but not any problem to fix if attended to before any rust occurs.
One of the major advantages to steel kitchen cabinets is that they are non-combustible. I know this from experience! In June of 1973, I decided I wanted French fries for lunch. I put the pan on, heated the oil, and put the potatoes in. Some of them got done before the others, so I removed them and left the others in to cook some more. I saw my neighbor girl Carol sitting on her porch, and I needed to ask her something, so went out onto our walk to talk. She couldn't hear me good, so I walked over to her, and got distracted. I had my back to our house, so didn't see anything, but a couple minutes later Carol said she saw smoke coming out the kitchen window. I said "my French fries!". I ran back over, saw the pan of grease was on fire, so got a larger pan and set over it, extinguishing the flames. The upper walls, ceiling, and wall cabinets were black with soot, and there were black streaks above the doors going into other rooms. The plastic wall tile behind the range had curled up, and some fell off. However, neither the cabinet above the fire, nor its contents, caught fire. If this had been a kitchen with wood cabinets, they would have caught fire, and there would have been major damage by the time the fire dept. could have arrived to put it out. It was bad enough as it was, with having to have six rooms cleaned and five of them painted. The cabinets were all professionally refinished at this time, and stainless steel installed behind the range.
Another advantage is they don't retain odors. If a mouse or other animal does its business in one, it can easily be scrubbed, due to a non-porous surface. Wood can be difficult to deodorize if anything soaks in.
As I've not done the new kitchen yet, I'm still deciding if I want wood, or to get new steel units. Most steel cabinets today are sold as "lab" cabinets, and not sold at kitchen dealers.
