If, like me, you want to be able to suspend disbelief when you read a book - then you'll have a problem with this if you are British. Whereas it is fine for the (American) translator to use American English in the sections set in Sweden, it simply doesn't work for the parts set in London - especially when 'English' characters speak American dialogue, using terms no English person would use. In general, too, the style of the writing is poor; I can't say if this reflects the original, or is again down to the translation.
The story is pretty conventional fare, and does not encourage me to repeat the experience with another book in the series. Not a patch on Fossum, Mankell, Indridason, Nesser or a host of other excellent Scandinavian crime writers, on this evidence.