Single Rear Wheel vs Dually - Whats the Best for You

Depends on truck type style. If you can go singles, carry the same weight in a given axle as duals, singles will carry more payload. Generally speaking, have better mph, stopping etc.
If given a choice, I'll take singles. One does not always have a single tire with upwards of 10,500 lbs per tire that is needed to carry a legal 20,000 per axle.
Marty