I have two friends who purchased hd16s and asked me to help them install them. (I was first to purchase and they bought theirs based on my recommendation ).
Installation is quite easy with one great big exception. The lower snap-on piece of plastic that covers the termination panel needs to extend downward in order to cover the wires better. In my case and theirs, it is impossible to make a clean installation that allows for, the incoming wires to be hidden. So, the beautiful RainMachine is made to look kind of crappy due to a lack of a longer cover (perhaps 2" or so) to hide the termination panel. This fix would add virtually nothing to your cost and really enhance the appearance of the finished installation. Maybe added perhaps as an option?