"[2] Schmitz is best known as a writer of "space opera", and for his strong female characters (such as Telzey Amberdon and Trigger Argee) who did not conform to the "damsel in distress" stereotype typical of science fiction of the time.

[6]John Clute writes in The Encyclopedia of Science Fiction, From 1949, when "Agent of Vega" appeared in ASF as the first of 4 stories later assembled as Agent of Vega (collection of linked stories 1960), he regularly produced the kind of tale for which he remains most warmly remembered: Space Opera adventures, several featuring female Heroes depicted with minimum recourse to their "femininity" – they perform their active tasks, and save the Universe when necessary, in a manner almost completely free of sexual role-playing clichés.

Many of his stories, as a result, focus less on moments of Conceptual Breakthrough than on the pragmatic operations of teams and bureaux involved in maintaining the state of things against criminals, monsters and unfriendly species; in this they rather resemble the tales of Murray Leinster, though they are more vigorous and less inclined to punish adventurousness.

"[8] In an essay in the anthology The Good Old Stuff (1998), Dozois laments that the book Agent of Vega is "long out-of-print, alas, but one which – if you can find it – delivers as pure a jolt of Widescreen Space Opera Sense of wonder as can be found anywhere."

However, the website Free Speculative Fiction Online freely offers Agent of Vega, along with several of Schmitz's other stories, including "Greenface", "Balanced Ecology", "Lion Loose", "Goblin Night", and many more.

[9] Gardner Dozois has said, in prefacing the Schmitz tale "The Second Night of Summer",[10] in which humans on the planet Noorhut face an attack from aliens and are, unbeknownst to themselves, saved by the actions of a single woman with psi powers, Granny Wannattel, with the sole help of a friendly alien she calls her pony: Schmitz was decades ahead of the curve in his portrayal of female characters—years before the Women's Movement of the '70s would come along to raise the consciousness of SF writers (or attempt to), Schmitz was not only frequently using women as the heroines in swashbuckling tales of interplanetary adventure—itself almost unheard of at the time—but he was also treating them as the total equal of the male characters, every bit as competent and brave and smart (and ruthless, when needs be), without saddling them with any of the "female weaknesses"—like an inclination to faint or cower under extreme duress, and/or seek protection behind the muscular frame of the Tough Male Hero) that would mar the characterization of women by some writers for years to come.

(The Schmitz Woman, for instance, is every bit as tough and competent as the Heinlein Woman—who, to be fair, isn't prone to fainting in a crisis either—but without her annoying tendency to think that nothing in the universe is as important as marrying Her Man and settling down to have as many babies as possible.