Coincidentally this is the second book in a row I have read that is written in the English of the Napoleonic Wars period (the previous being Fire Down Below). JS&MN is the more mannered of the two. It also has a lot of footnotes and a lot of digressions into short 'folk stories' and 'urban legends'. I like all that sort of thing a lot, for example in House of Leaves - which shares, oddly enough, one or two other similarities with this otherwise very different book. However, you know for yourself whether that sort of thing gets on your nerves or not.
I read a very misleading review of this book, which put me off starting it, that said that it was dry and repressive and positioned 'magic' and passion as purely destructive forces. I don't think this is the case at all. The first 100 pages are quite dry, for two reasons. Firstly they centre on Mr Norrell who is a humourless, passionless, self-centred git. Secondly, they set up a dull conventional almost magic-less social milieu, so that one is literally yearning for the excitement and glamour (in both senses of the word) of magic to intrude and mess things up. That means that magic can be shown as dangerously seductive but not constructive or good.
The book uses two styles of writing: mannered, ironic, humorous social prose to represent human society, and a wilder prose, reminiscent of William Blake and Emily Bronte for example, to represent the incursion of magic. The effect is like veins of glittering moss breaking open a clean pavement. I think it says something very accurate about English literature, and by extension our country and our culture.
Another triumph of the book is the creation of a range of interesting and attractive characters. I'm going to do a second post just about the characters, perhaps later today. Most of the central and active characters are men, and I think Clarke does a good job of making them attractive sexy characters. There are few female characters, and little sexual action, but I don't think this is a big problem - although it worried me before I read the book. The characters develop well, and one or two of them are fascinating.
My main criticism is that some of the magic employed in the middle stretch, for example in Spain and Belgium, is a bit silly and a bit too easy. However, speaking as someone who almost never reads fantasy or magical realism even when well written, because it usually seems pointless and uncompelling, I found this book more than readable - it has enthused and inspired me. Highly recommended.