Is a sleeveless button-down shirt actually wearable?

Yes, mainly as a summer or resort layer. Wear it open over a plain tee, or buttoned on its own in hot weather. It reads casual, so it pairs better with shorts or linen trousers than with a suit.

How does it compare with a short-sleeve Burberry shirt?

The short-sleeve version is more versatile and easier to style for everyday wear. The sleeveless cut is cooler and layers more cleanly under a jacket, but it is a narrower look.

What is the fabric and how should I care for it?

It is 100% cotton with a button-down collar and two breast pockets. Machine wash cold and hang dry, then iron the collar and placket to keep the shirt crisp.

Does it run true to size?

It follows standard men's shirting sizing, so take your usual collar size. If you plan to wear it open over a T-shirt, your normal size gives a clean fit; size up for a looser layer.