I think there is more than the odd decent area. Moortown, Adel, Cookridge, Horsforth, Roundhay, Temple Newsam, Oakwood, Shadwell for examples.
The council estates were solid built houses but turned into slums by some of the tenants that lived there. The biggest problem was building sub...
There are some very expensive areas in Leeds. Every city has it's run down areas, but Leeds also has some very nice places too. It's better than most West Yorkshire towns/cities.