I purchased the AAS-500 system, which appears to be the same as the 600, but with fewer sensors. The installation instructions were perfectly clear. All the door sensors came with the batteries already installed, which was nice. The motion detectors came with the (9v) batteries, and were easily installed. I got this system to replace a 1996 system from Radio Shack which had failed. A major difference with this system (in addition to the much better quality) is that the outside siren can be mounted without worrying about physically connecting it to the console.
Prior to installing sensors I read the entire instruction manual then made a list (map) of what was going to be installed, and where, and numbered each sensor per the instructions. I wrote the numbers on each sensor. I then activated each one and tested them, one by one to make sure everything worked properly. Then, I mounted each sensor per the map I had made. One of the door sensors failed to work. This is when I discovered that the magnet must be placed on the right side of the sensor containing the antenna. I removed the sensor and replaced the backing with one of the extra sensors and mounted it with the antenna pointing down. I should have tested this aspect before actually mounting it and ruining the sticky tape.
The motion detectors have a one page instruction sheet, which really does not need to be read. If you do read it, you will find it pretty choppy; very poor English.
In summary, this is an excellent product, very good quality, good instructions and a major step forward in terms of technology over the system I was previously using.