I agree with you, David, except for one thing. Even were he to lack the elements of "cosmic vertigo", Vance would never fall into the pure utilitarianism of an Asimov, precisely because of the ironic component, which is the dominant aspect. This is completely lacking in Asimov and others of that type.
Think, for example, of Gersen's description to Navarth of the workings of the Jarnell Intersplit. One way that this can be read is as a satire upon all the the pseudo-scientific descriptions of various "hyperdrives" which were, and are, the staple of hard sci-fi.