It is a pity that, in his first novel, he did not have stronger editorial
guidance than is apparent in the book—for he can write very well—
even though most of the time he just lets his pen run on. (kirkus)

Gaddis is a cynic but he's young. (desbarats)

A literary event, of sorts. (newsweek)

the polysyllables, sentence fragments and foreign words give the
novel too "arty" a tone. Sometimes these devices are effective.
  But please, Mr. Gaddis, not through all 956 pages. (dixon)

But Please, Mr. Gaddis, (dixon headline)

Mr. Gaddis is in the modern tradition of pronoun misplacers whose
leader is another William, the man from Mississippi, Faulkner. (lay-
cock)

Occasionally this author shows some depth or perception; and he
apparently can manage a narrative. And if, please God, this book is
not a "success," he may meet up with some human beings whom
he can use as characters. Then perhaps he will really write. (hill)

  WHAT THEN are we left with at the end of this novel besides
tired eyes, an unchallenged brain and a feeling of frustration? The
book is large but the scope is small so the comparison with Joyce
is out. The author's wit, irony and erudition we will grant. We will not
yield on rich diversity, however, and we must point out a certain
amount of immaturity.
  And we cannot agree¹ that Gaddis has surpassed Eliot in the de-
lineation of the Waste Land. Rather, like the streets in Prufrock, this
novel leads you like a tedious argument of insidious intent to an
overwhelming question:
  Is the book at least a magnificent failure?
  And we must reply that there is nothing magnificent about it. And
we go back to rereading Joyce's "Ulysses" for the umpteenth time.
(bass)