No, CAS didn't alter that evaluation; he essentially gave up prose writing following that productive period of the 1920s-30s, after that writing only occasional tales; verse he never stopped writing.

Poe? Look at his essays and letters -- he said repeatedly that he vastly preferred verse over prose, and certainly his abilities as a poet show how just that preference was, as he remains one of the greatest (not to mention most influential, even influencing T. S. Eliot in "The Waste Land") poets America has ever produced.

While it true that each has its place, one of the reasons verse is seen as a superior form (think, for instance, of the use of the word "prosy" to describe someone of more mundane, prosaic mold) is that poetry by its essence tends toward more subtlety and concentration; prose dilutes that effect in most instances. To use one of my personal favorites from CAS's verse, think of "Medusa", where he describes the victims of the gorgon scattered around the head:

"... As round an altar base,
Her victims lie, distorted, blackened forms
Of postured horror smitten into stone --
Time caught in meshes of Eternity --
Drawn back from dust and ruin of the years,
And given to all the future of the world."

That little bit, particularly the line "Time caught in meshes of Eternity", which I think is one of the finest lines Smith ever wrote, in fact one of the finest in all modern verse, is something which simply could not be captured in prose with such intensity and brevity. Poetry is the essence; prose is the diluted product.

This is not to say you can't have fine prose, as a number of writers had and do; but it can never really approach that incisive yet multifaceted quality which poetry -- not versified prose, as one so often encounters with, say, many of the eighteenth-century figures, and the vast majority of modern verse -- has as its very heart.

Funny me saying all this, given that, save for a very few pieces (largely by Poe), I was never much of one for poetry until I was almost an adult; since then, my admiration for the art has grown tremendously, and continues to do so the more of it I encounter....

My list is:

W. H. Hodgson
Algernon Blackwood
Arthur Machen
C. A. Smith
A. Merritt
Lovecraft
M. R. James
E. A. Poe
Le Fanu
Dunsany

Shakespeare (I know him, but never have read anything by him though I have his books of sonnets)
John Keats (I know the name, never have read anything by him)
Jack Vance (frankly, I have never heard of him)

My personal list would be:

W.H.Hodgson
M.P.Shiel
Arthur Machen
Algernon Blackwood
Maurice Level
John Metcalfe
Leonard Cline
Samuel Warren
C.A.Smith
H.P.Lovecraft

this is a fascinating thread - just to stir the pot a little - I would add what I think may be the finest prose work of the 20t century - Mary Webb's "Precious Bane" - try it,you'll like it - and learn an easy cheap way to get rid of Grandma