I have one on every faucet on my house, they ROCK!
Some use the quick disconnect so that they can switch to a foam gun or something else quickly, for me I don't have that...they are a bit expensive but the Craftsman one that I have is indestructible or seems that way.
I use one and like it because I just twist the end of it and get a constant flow of water whether it is a jet or light mist. I haven't used a trigger nozzle in a very long time. Plus the one I have is hard rubber = less likely to scratch the paint if it were to fall.
these things are awsome. best money you will spend. You can change the presure to adjust to your needs, they are cheap and work awsome. Like bemerboy said i would get a quick disconnect. I dont use a foam gun but they work well for when you want to rinse the car