Dragonsbane was an amazing book, and a little while ago I happily acquired the 2 sequels Dragonshadow and Knight of the Demon Queen. I read Dragonshadow which had far too much about demons rather than dragons, and seemed rather uneven. I delayed reading this one as I didn't want more demon stuff! but have now done so.
It reads a bit like a book Barbara Hambly didn't want to write. There was some interesting stuff about Jenny - the witch in Dragonsbane who got much more magic in Dragonshadow and then lost it at the end - going through the menopause. Some of the action seemed really surreal and there were certainly inconsistencies with the first book. It rather came to life when John Aversin (Thane of the Winterlands and partner cum husband to Jenny, father of their now 3 children) ended up going through various hells to a futuristic city land (aka Hell of Walls but not truly a hell) more analagous to our world. He was befriended by a group of nerds who wanted to be wizards. Meanwhile Jenny was off trying to rid herself of demon possession memories and save her son and others, sometime turning back into a dragon, finding demon possession problems all over the place. She returned to prince Gareth to warn him about the demons but then seemed to completely forget about this and move on to trying to deal with a plague - I won't tell you about the ending but don't expect to enjoy it!