or any other district with specialty shops

In my town, if you need to do renovation, there is a part of town where all shops that sell tiles, sinks, paint and toilets are. If you need that product you go to that part of town.

Furniture, flowers, cars, pets all have their own district. When you then actually go to these places, then all shops have pretty much the same selection, same prices etc.  Convenient that you can check lots of different shops easily, but as they all have the same products and no big price differences, then no point. Highly inconvenient for those living across town. Of course I would guess that the big cities could support more than one toilet district. 

The only thing that appears to be truly spread all over town are the KTV's and China mobile shops.