How is this different from a regular hair dryer?

It is a hot air brush: heated air flows through a round brush head, so you dry and shape at the same time. A regular dryer only dries; you still need a brush and technique to style.

Is it good for short hair?

The round brush head is large, so it works best on shoulder-length or longer hair. On very short cuts or tight layers the head can be hard to maneuver close to the roots.

Does the charcoal actually do anything?

Charcoal infusion is the line's marketing focus, aimed at smoothing and reducing odor and buildup. Expect the main benefit to come from the heat and brush action, not the charcoal alone.

Can I use it on wet hair?

Yes, that is the point: it is meant to dry damp hair while styling. Towel-dry first so hair is not dripping, and use a heat protectant.

How does it compare with the Revlon One-Step?

Both are one-step hot air brushes with a round head. The Hot Tools is the more premium option with a charcoal-infused design; the Revlon is the widely known budget pick. Performance is close, so pick on head size and feel.

What should I know about cleaning it?

Hair and product build up in the bristles and on the barrel. Remove loose hair after each use and wipe the barrel when cool to keep airflow and performance steady.