I never read any Van Vogt but like this piece from PKD from the Vertex interview:
DICK: I started reading sf when I was about twelve and I real all I could, so any author who was writing about that time, I read. But there’s no doubt who got me off originally and that was A.E. van Vogt. There was in van Vogt’s writing a mysterious quality, and this was especially true in The World of Null A. All the parts of that book did not add up; all the ingredients did not make a coherency. Now some people are put off by that. They think that’s sloppy and wrong, but the thing that fascinated me so much was that this resembled reality more than anybody else’s writing inside or outside science fiction.
VERTEX: What about Damon Knight’s famous article criticizing van Vogt?
DICK: Damon feels that it’s bad artistry when you build those funky universes where people fall through the floor. It’s like he’s viewing a story the way a building inspector would when he’s building your house. But reality really is a mess, and yet it’s exciting. The basic thing is, how frightened are you of chaos? And how happy are you with order? Van Vogt influenced me so much because he made me appreciate a mysterious chaotic quality in the universe which is not to be feared.
Wikipedia courteously offers these bits of commentary from Damon Knight’s criticism, mentioned above:
“The World of Ā abounds in contradictions, misleading clues and irrelevant action…It is [van Vogt’s] habit to introduce a monster, or a gadget, or an extra-terrestrial culture, simply by naming it, without any explanation of its nature…By this means, and by means of his writing style, which is discursive and hard to follow, van Vogt also obscures his plot to such an extent that when it falls to pieces at the end, the event passes without remark.”
And his 1974 walk-back:
Van Vogt has just revealed, for the first time as far as I know, that during this period he made a practice of dreaming about his stories and waking himself up every ninety minutes to take notes. This explains a good deal about the stories, and suggests that it is really useless to attack them by conventional standards. If the stories have a dream consistency which affects readers powerfully, it is probably irrelevant that they lack ordinary consistency.