The CTMU most definitely is a monic (non-dualistic) theory, meaning that it asserts that reality is reducible to a fundamental syntactic medium that distributes over all of reality. In simpler terms, everything is made from a fundamental substance - everything is different (e.g. apples and oranges), yet is reducible to the same underlying reality. If they weren't reducible to the same fundamental medium/substance, it would be impossible to compare them, even to hold them both in the mind simultaneously, as they would not both be real or occupy the same reality. Yet, despite it being a monic theory of reality, he does say that it is a dual-aspect monism, meaning that this fundmental monic medium/substance has two aspects, those being mind and physicality, inseperable and complementary.
I take slight issue with the suggestion that Langan has not used direct experience in deriving his theory. It seems obvious that direct experience of reality was the impulse at the inception of his quest for an ultimate theory of reality, and he has relied on the modern body of scientific discovery, which is derived empirically - by physical experience. And he has expressed that he has had spiritual experiences related to the contents of the CTMU, so I think we shouldn't be too quick to dismiss his spiritual capacity/progress. (It is also arguable that all experience in some sense has a conceptual or cognitive aspect. This idea is one of the central themes of his theory, that everything in the universe follows the same fundamental rules of cognitive-perceptual syntax, meaning that everything from your perceptions to large physical rocks in quarry have a conceptual and logical aspect to them.)
I agree that Leo's descriptions of God and of ultimate reality share a similar underlying structure and similar ideas with Langan's, despite them using quite different terms and methods of explaining. Both of them reaching similar conclusions though different paths is not that surprising since they're both brilliant and I would guess that the absolute truths of the univers would funnel such individuals towards the same end-point despite arriving from different starting points.