Randy, to me your comment sounds like an extraliterary appeal intended to secure for Nevill a literary position he isn't aiming for and doesn't achieve. But thanks for the comment.
Um... Okay. Let me try again, though it may remain extra-literary since it's my impression of how writing works which may or may not reflect reality, so feel free to correct me.
James' stories hold a special place, like Doyle's Sherlock Holmes canon. Most writers who try to tap into what makes such stories special produce work that rarely has the elan of the original (even the older Doyle occasionally had trouble matching the younger Doyle). What I've read of those inspired to write James-like stories, some are passable (say, Munby's "Herodes Redivivus" -- which also has a rather distasteful subject) and some are not.
Other writers take the structure or the premise or some aspect of the stories and turn them to their own uses. This can produce good work "in the tradition of" as opposed to pastiche; I would put Fritz Leiber's "Smoke Ghost" in this class since it changes the location of James, employs a different class of protagonist, and modifies and extends the Jamesian ghost story in a way I doubt James would have approved.
The latter is Nevill's approach and within the parameters of what he's attempting, I found his novel successful: The bones of the book are the Jamesian ghost story, but the fleshing out exceeds the normal length of a James story. Writers write what they know, and while Nevill knows St. Andrews and at least some of the workings of the University (having studied there) he also seems to know or intuit the ways of a poor young man with aspiration be a rock musician. And let's not entirely extract James from his milieu: At the time he wrote, he wrote from a very narrow perspective of the well-off at school or in a similar elevated social environment (a social environment a contemporary, Saki, often mocked mercilessly); even Doyle showed a wider range of the seamier side of life, and contemporaries and near-contemporaries of James wrote of, say, the life of the Irish poor in much earthier terms. So if you're not fond of the earthier mixing with the Jamesian story, blame Leiber.
Further, Nevill's approach to the threat would doubtless have troubled James in much the way I assume Leiber's approach would have: There's evil out there with powers that to us would appear god-like.
Just to cover other bases: Nevill, and Leiber for that matter, does not write with the elegance of James. It's one of the traits of James' stories that appears hardest to match, equivalent in effect on his work to Doyle's spare and direct writing style on his stories.
So, to sum up, Jamesian but not slavishly so, mainly in underlying structure; content arguably seamier than James and so losing the effect of James whose settings were probably as idealized as Doyle's London, but aiding in establishing the verisimilitude of time and place and characters.
From there, the next decision belongs to the reader: Do I like this sort of thing? Sometimes I do, and this is an instance where I think the writer was mostly successful. Does he reach the heights James reached? Well, no, but then James didn't always either and was still entertaining all the same. Further, the book scratched a personal itch as I'm curious how a form of literature can be adopted by later writers and applied to the social, cultural and political reality in which they live. Critics have often complained about how confining genre is, but I think that's a short-sighted view: Over time genres change and transform and those transformations may offer a good deal of insight into the time and place in which they happen, and even some insight into what we call the human condition.
Bet no one knew it was Long-Winded Tuesday. I'll stop now.
Randy M.