A few years ago I had a job where I needed to set up a 80,000 square foot pad with dual slope and repeat it every day for a couple of months for all the other subcontractors. I purchased a Gl522 kit with a remote and two HL750 receivers. These receivers can talk to each other so one can display the reading of the other. I set up a fixed mount for the laser and a fixed mount for one receiver (for aligning the laser), both on the structural steel of the building and a couple of hundred feet apart. Every morning I would set up the laser and the alignment receiver on their fixed mounts, set the other receiver that I held in my hand to display the fixed one (since I could hardly see it at this distance), then rotated the laser as necessary to get and on grade reading Worked slick, the only thing I noticed was at a few hundred feet, the laser would sometimes drift up and down maybe as much as a half an inch during the day. I don't think these are as stable as their more expensive cousins, like the 722. I have used the 522 as my daily laser ever since with no complaints. I always thought the dual linked receiver thing would be cool to have one receiver in the cab, displaying what the grade checker was seeing with his receiver. Haven't done it yet, but many times I have had grade checkers that have trouble communicating what is going on and seem to always have the receiver turned away where I cannot see it. Like Shimmy1, I am a fan of the CR600 receiver, and keep one of these in the laser case for everyday use. Oh, and I would never buy a laser without a remote again. Been way more handy than I ever would have imagined.
