Why get a refractometer?

I'm just curious what a refractometer accomplishes that a hydrometer does not. It seems that you need to use a set of tables to correct a refractometer for alcohol content, which is another step in what is already a very simple process. I'm just curious what is better about them.

Just a drop is needed, which helps with small batches. It also is quick to cool off a spoonful for rapid measurements when making volume adjustments to hit the targets. Conversion is minimal issue if you use software. For example Beer Alchemy's recipe instruction sheet lists both the Brix and Plato targets. I will disclose that I've never used the hydrometer that came with my original starter kit. So I'm obviously biased.

Refractometers shine in on the fly measurement of wort on brew day, especially if you are doing all grain. They are invaluable when fly sparging. You don't have to cool the wort and it only takes a tiny sample. They only need correction when alcohol is present. During or after fermentation the only advantage is the smaller sample size, the draw back having to correct for alcohol content. Even after correction they aren't particularly accurate in the presence of alcohol.