Do not use ADT!
Had system installed in Sarasota, FL yesterday by technicians who showed up late.They used "tag team" and "bait and switch" techniques to upsell me.
I was told by sales that having a landline was a good thing, then told by them it was bad. That allowed them to sell me on the more expensive system which added to my monthly bill. Then told how the standard sensors aren't nearly as effective as the - you guessed it - more expensive ones they wanted me to buy. Here's the icing on the cake - the unit doesn't even work!
One of the sensors won't allow me to arm the system.I am canceling the contract - via registered mail requiring signature as well as faxed notification) but after reading other reviews and all the complaints on the BBS site (731 pages by the way) I already know this is far from over.