Gilmore sprinkler gives you a lot of control of how far the water shoots and the shape of the circle. I have been using it now for two weeks, and I am very pleased with its performance. This is my first sprinkler of this type so I got a bit soaked figuring out how to set it up exactly as I wanted, so I am adding detailed instructions and photos of the controls.
My goal was to set up a 220 degree semi-circle, leaving a small wedge where I can exit the basement and approach the sprinkler without getting soaked. The distance of how the sprinkler head rotates to the left or the right is controlled by two red levers around the head. The lever on the RIGHT hand side control how far the head rotates to the LEFT, and the lever on the LEFT hand side controls how far the head rotates to the RIGHT. (see photo)
The distance of how far the spray shoots is controlled by a red ring which pushes on the back of the head. The higher the ring is lifted the shorter is the spray, when the ring is at its lowest the water shoots the furthers away. How high the ring is lifted is controlled by the pegs that you can reach beneath the sprinkler (see photo of the sprinkler upside down). When you push on the pegs from below they raise the ring. When you push on the ring from above, you lower the ring. You can control each individual peg, so you have a lot of control and can create a pretty intricate shape for your watering needs.
If you need to the sprinkler to make 360 circle, you need to pull the medal clip towards you.
The sprinkler comes assembled with female hose-end connector with shut-off valve and male hose-end adapter. For some reason the sprinkler's shut-off valve does not want to stay facing up, so I found it easier to turn the sprinkler on and off using the shut-off valve on the spigot.
I have been watering the newly planted lawn twice a day. The sprinkler is working very well. I am pleased with precision of the watering I was able to achieve avoiding various areas that should not get wet yet getting water to everything I wanted to water.
Updated 10/13/11
After 4.5 months of twice a day daily use the sprinkler was still going strong when I packed it up for the winter. I am still very pleased with it.