Has anyone actually seen an officer wear a cape? Is this an outdated piece of clothing? Pictures? Thoughts?

Sir,
Thanks for the response. I think you're the first person that has told me they own one. Do you wear it with blues, or asu?

With ASU. I'd have to look again, but I don't believe it is authorized with mess dress.

I have a US Army Officer's cape as well.

Per DA PHAM 670-1, Chapter 20-7, it's authorized with ASU, dress blues, mess dress, and evening mess dress.

I got married in my dress blues and officer's cape 10 years ago. It is much easier to wear a army saber with a US Army officer's cape. My cape is also lined with my first named color of my basic branch.. Infantry Blue.

Department of the Army Pamphlet 670 – 1, Chapter 20-7.
Uniform and Insignia
Guide to the Wear and Appearance of Army Uniforms and Insignia

b. Cape, blue, male (officers only).
(1) Type. The cape is an optional purchase item.
(2) Description. The blue cape will be made from an approved specification or pattern. The materials are wool and broadcloth, dark blue in Army shade 150; wool and gabardine, dark blue in Army shade 150; wool and elastique, dark blue in Army shade 150. The cape will reach to at least the midpoint of the knee, but it will be no lower than 2 inches below the knee (see fig 20 – 7). The lining of the Army blue cape is rayon, acetate, or another synthetic fabric with a satin face and wool nap back in one of the following colors:
(a) General officers. Dark blue.
(b) All other officers. The first-named color of the basic branch.
(3) How worn. Officers may wear the cape with Army white and blue dress, mess, and evening mess uniforms. Enlisted personnel are not authorized to wear the cape.

Most officers don’t buy one because they are expensive and optional and there are few occasions for wear. I still have mine that James S.Lee made for me in 1963. The few times I had occasion to wear it, senior officers made remarks about Zorro and Batman. It looks fantastic when photographed astride a horse!