Not that it doesn't have redeeming features. Ms. Clarke's writing has a very sly, dry wit. Today, there was actually a passage that made me laugh - Jonathan Strange has been performing magic for Lord Wellington in the Peninsular Wars. After he moved a river to a different location, Lord Wellington remarked that "there was nothing so wearying for troops and horses as constant marching about and that in future he thought it would be better to keep them all standing still, while Mr. Strange moved Spain about like a carpet beneath their feet." (If you don't find that funny, don't bother trying the book.)
I believe I would greatly enjoy the story if it were about 300 pages. But 3 times that long - most of the time there isn't enough going on to hold my attention. Still, thanks to Mr. Prebble, I believe I will finish it this time...