I think it's quite good.
I think it (rather gently) breaks new ground, but at same time isn't trying to be anything more than a Novella (haven't seen that term in a while).
I also like that it seems to me a sort of oblique "answer" - or re-thinking - of The French Lieutenant's Woman. I wonder if it is, on purpose, at all? As it makes a nicely thoughtful riposte to the posturingy bits of John Fowles.
Separately: anyone seen any nice side-zipped narrow-legged linen trousers anywhere?