Just had a friend install a remote starter for me. I paid him $100 for it and all the associated little wiring and bits, plus a case of beer to have him install it (he used to work in a car audio shop). All I can say is, I really wish I'd done this a lot sooner. It's going to be soooo nice ot come out to a nice warm car instead of having to babysit it for half an hour while the ice melts off!
One thing I can say is, this install was waaaaaaay more complicated than anything I would have been able to do. He's a pro, and it took him over 2 and a half hours to install it, plus another hour or so before that to get the starter wired up with the appropriate relays, etc. This would have taken me days, at least. He also had to use his tester to figure out the right wire in a few cases, even though he had the tech sheet for the car. Maybe it'll be different with the one you get, but this install was NOT easy.