Just installed one about a month ago. Went in very easy, but I do have some experience with electronics. I basically stripped the jacket off the wires I need to attach to and soldered. Only a couple wires were cut to break the circuit and run through the box. It is programmed via a PC and there are 2 sides to the unit. Security and Remote Start. Both are programmed individually (this is something that took me a bit to realize). The box is amazingly small, a little larger than a deck of cards.
There are a couple things that I don't like, but I think they are just setting I need to change for my preference. I haven't had the time to make the change. One of them is that the doors relock after the cargo doors have been closed. I am concerned about setting the key down and shutting the door.
Happy with the purchase. Glad to be able to use the OEM remote to activate the remote start.