We had ours put in when we built our house, so as far as the major wiring goes, I don't know because it was all done with the rest of the house.
We hit two snags and if we ever build again I will make sure these things are spelled out up front:
We have motion detectors and although we told the salesperson while he was writing up the order that we have a small dog, it was overlooked when the detectors were installed. Apparently they can tilt the sensors at a slightly higher level but this wasn't done like it should have been.
Secondly, the salesperson wrote the entire order up and gave us a price. When we decided to go with it, we let him know that we didn't want it monitored, just the equipment installed. Well, then it was a totally different (much higher) price if we weren't going to sign a 2 year contract. We were in a time crunch with our builder ready to drywall, so we said, whatever, go ahead and we'll have it monitored for 2 years. When the 2 years was up, and we went to cancel it, the salesperson had wrote our contract up for THREE years. Our fault for signing and not looking, but I know what he told us.
So....my only advice is, know what you want up front, let the company know clearly BEFORE they give you a quote, and if you have time (which we didn't) get quotes from a few different companies.