I loved the Scar. Thought it was much better than Perdido Street Station. I know Mieville gets a lot of praise for New Crubozon (and rightly) but PSS was so claustrophobic! The Scar had a much wider scope, and the characters where so much more colourful and enjoyable. Uthor Doul especially is a brilliant character.
The ending was still a let down (Mieville's only flaw, IMHO - he can't write proper endings) but it wasn't as bad as the ending to PSS. And the rest of the book was so awesome I'll forgive him