Go cruise
I have had mine for about a year now, it works fine and my bike will cruise on a level superslab for about 10 minutes at one speed until I need to make a small adjustment.
That is just due to the engines vibration.
A friend of mine has one and his would need more adjustment, what he did was loop a small length of wire thru a hole in the upper arm and around the bottom arm of the Go Cruise and he tightened it up to the point where it stopped moving while he was riding.
Now he's happy with it, works perfectly.
Incredibly simple design that works just as well as any of the other expensive ones out there.
I am still thinking about installing an electronic cruise control sometime in the future.