Ah yes. All that is correct, to a certain extent. I run a special tool to find the quickest dns servers for me (or location I'm at.) Then I set the router to make all requests to the fastest server, always.
Very often, it is much much faster than even the ISP's dns servers! I like to disable caching because then there is no chance of poisoning or just plain normal errors.
Here is the utility I use to find fast dns servers that are free to use. Opendns is extremely fast but there are many others. Right now, my routers are using 4.2.2.6 for dns requests.