I really like my Metro Blaster, easier to use than a leaf blower since you just have to hold the nozzle and the flexible hose attached to it, much easier to dry roofs and hoods that way and you are closer to the point where the air is coming out and can see the results better. I've found that it gets more water off the car than a leaf blower.
In addition to drying freshly washed cars I've found it to be useful to dry cars that need washing. For example if I drive home in the rain and pull into my garage my car is dirty and wet. I don't want to just leave it to water spot but I don't have time right then to wash it. I get the Master Blaster out and blow most of the water off the car, nothing touches the car except air, and what little water is left evaporates. When I have time later on to properly wash the car there are no water spots to deal with.
Another use is during the summer when those sudden rain storms come up and get a car sitting outside wet. The sun comes out blazing and tries to water spot the paint because you've got water beaded up all over the car. I use the Master Blaster to again blow the majority of the water off the car and what little is left evaporates without water spotting. I have a 20 amp GFIC outlet right at my garage door.
Very useful tool IMO. Of course a leaf blower could also do the same job but it's bulkier to use than the Master Blaster.