For a lot of readers, it looks like it was. I picked up the book because it carried praise from authors such as Philip Pullman and M. John Harrison -- the latter found the book 'raucously funny' (really?! I lolled once).
Reading the blurb, I (unfairly) expected something like Angela Carter -- colourful, fantastical, absurd, humane. Mantel is rather more interested in the banalities of suburban life, which she depicts with a wry irony that prevents outright boredom, but does not provoke the kind of horror The Office conjured up, which I find the only appropriate response to the subject.
Trips to buy sheds and visit GPs are described in wearying detail. Such diversions are not pointless. They serve to illuminate Alison's benevolent character in contrast to her partner / assistant Colette.
Colette is my biggest problem with the novel. The reader can understand why she is monstrous, but the extent to which we have to put up with her can be trying. Not only that, but Colette's P.O.V. infects parts of the book, casting other characters (Gavin, Evan, Michelle, Suzi) as emotionally stunted simpletons -- nothing more than targets for Mantel's satirical barbs.
The most interesting aspect of the book is Alison and her past, her interaction with the dead men who abused her as a child -- emotionally, physically, sexually. This is tough subject matter, and I think Mantel deals with it in an original and valuable way. I just wish I didn't have to read thru all of Colette's self-righteous bullshit to get to it.
Mantel has an essay in the back of my edition called 'Revering the Gone-before', in which she clarifies that she finds the medium's belief-system 'threatening, unlikely, and slightly repulsive'. Reassuring, as in the interview she is more equivocal -- 'I don't take up an attitude to Alison's trade. I am not a believer or unbeliever'. In the book, spirit world is the real deal. The prospect that it is all imaginary is not considered seriously, a one-sidedness I was not entirely comfortable with.
The essay highlights some of the concerns Mantel was grappling with in writing the novel -- 'the thing that frightens me most is confiscation of history', 'a lack of roots that doesn't even define itself as a lack'. This is interesting for me partly because I don't entirely understand this fear. Mantel suggests that not knowing or caring about your past means it can be changed behind your back by others. This is true, and dangerous. We should always have a firm grip on history to ensure it isn't falsified. It's Mantel's focus on personal history ('wondering where we came from') that is new to me. I think history is valuable as a resource of accumulated human experience that can inform our awareness and actions in the present. It has to be as accurate as the evidence allows in order to do this, but it doesn't have to be my own personal history. Mantel is talking about something else -- externally imposed gaps in memory that prevent the identification and treatment of trauma. And about something else again -- the interest some people (fewer than Mantel suggests, I think) have in their own family trees, their 'roots'. Individually, these concerns are worth exploring, but I don't know what is gained by linking them all together. I suspect this chain of associations does not produce a particularly coherent overall picture.