The base with temperature control and a fine-ish tip is what makes them good, I think. The older Radio Shack pencil soldering irons had a fat tip, one temperature.

The nicer stations like Hakko's have very nice metallurgy in their tips as well.

As soon as you get a station too there's a little sponge, maybe some metal wool — these things you can use to clean the tip of the soldering iron. That in itself encourages good soldering hygiene and makes for better soldering.