Yeah, ive done a lot of work with it this summer. You can easily outrun it at normal speeds, even going slow. If you want it to keep pace you have to go dead dead slow. Since that is out of the question, all i do is make a pass, then measure, then take however much it says i have "left to dig."
Other issues, the laser sensor is connected to a sender that transmits to the reciever in the cab. In order to bench off the laser, you set the stick so you have green flashing on the laser receiver. This sends voltage to the sending unit, which takes a sec to start sending a rebench signal to the controller in the cab. This whole process can take up to 5 secs, which feels like 5 hours.
The other day the wire broke on the laser receiver. Called the dealer and he told me to keep me going just to get the green lights flashing, and hit the "zero on laser button" which actually works much faster than waiting for it in automatic mode.
Long story short, don't pay the extra for the automatic benching kit, it works better without it.
It hangs every once in a while, but toggle the power and your going again in a few seconds. (Its windows based and hanging is what windows does best)
But other than these nuisance problems, you can definitely dig to grade better than you could with a stick man, and do it faster and cheaper. You never wait for the stick man to move his butt, or to get out of the way. I think that if you are really good at holding grade, the benefit diminishes because you don't need the stick man as often either. But for someone who isn't great (read bad) at grading, it means i can actually do the job. Without i'd be parked.
All in all, it works well for me, and it is generating interest for my machine.
Ken
