We have had great success using a house type swamp cooler in the desert. We therefore are considering a turbokool swamp cooler. Has anyone tried using one. I am primarily concerned about capacity (we have a 40 ft motorhome) and would be trying to cool either living or bedroom ( based on which window is cracked open to exhaust air).

You mean like Mac and Chris did here -http://www.macandchris.com/AirConditioning.htm? They started with a TurboKool and eventually moved to a more powerful Solar Chill unit.

We had a turbokool unit in a 25ft winnebago motorhome. The only way we could stay cool in 80 degree plus outside temp was to stay right by the turbokool output. If we left that area, the rest of the motorhome was hot. Everything was operating properly on the turbokool, the winnebago had good insulation from the heat. We just couldn't stay cool enough unless the air from the turbokool was blowing directly on us.