Very easy to install. Base monitoring is $14 per month, but went with upgraded monitoring with links to iPhone, text messages on status, etc for $24 per month. Their equipment links directly to through cell signal (customer does NOT get involved with cell companies, that is part of Simplisafe's monthly fee). NOTE: Their default cell linkage is through T-MOBILE. Didn't have good enough signal from T-Mobile; they switched out linkage to use Verizon. Great signal through Verizon. If you order from them and do not have good T-Mobile signal in your location, be sure to let them know so they can provide Verizon linkage equipment.||All sensors, motion detectors, and keypads were easy to install. They come with 3-M adhesive strips attached -- just peal off protective strip and press into place. Decided to move keypad after first few days. No problem AS LONG AS YOU FOLLOW THE DIRECTIONS. ||Very easy to customize the system. Can be done from keypad but is far easier to do online. Can set delay times for entry and exit, multiple pass codes (with identification for each so you can see who was in the house, can set which sensors/detectors are active when you set the "home" setting for partial coverage while you are in the house, how each sensor/detector reacts to being tripped when the full alarm is active, etc.. ||If you have the $24 per month monitoring instead of the $14 per month monitoring, you can set up what (and when) information is texted and/or emailed and to whom.||Other detectors (e.g., smoke, water leak, temperature) are available but haven't added any of them yet. Most are priced about $29 and it looks like it is very easy to link them to an existing system. From what I remember, you can have about two dozen sensors linked to a system. (Adding extra sensors does NOT change the monthly monitoring fee -- the one time cost of the sensors is it). ||Most of the sensors have 5 year batteries that can be replaced. The keypad has 4 AA batteries that should be changed annually. The base station plugs into a normal electric outlet, but has 4 rechargeable AA batteries in case of electric failure. I personally will probably replace these rechargeable AA batteries when I replace the 5 year batteries in the sensors.