Billt,
I am in the process of buying and setting one up. This does not mean it will happen this spring due to the rapid pace I don't move at, but it will happen this summer.
What convinced me, besides the fact I teach and preach at people to do it, was talking with fellow instructors who took the step to do it themselves and love them. I have not heard from any of them that it was too difficult or that they had issues understanding, and none of these guys are geeks or nerds. They are gun and safety people who would still be using soup cans and string for phones if you could buy buttons in the store

Their advise to me, and what I am doing right now, is read the information, read the reviews, talk to the people at the stores who sell the stuff, and just like any tool, buy the best you can afford.
Our yard is 7 1/2 acres with six main buildings. I am looking at/for an eight camera capable, wireless system, with clear regular and inferred modes to pick up the different buildings from other areas. At this time I am not looking at interior cameras due to the layout of our home, but my sketches show that with an eight camera system I could cover the main part of the yard, the exterior of the house, and still have two in the house. I have been looking also at a twelve camera system that would do all I could dream of, but a little out of my range. There is also the possibility of putting in two eight camera systems - This would do all I wish and leave room for adding on as I learn what I missed.
You might have picked up through the previous paragraph why this is not a quick move for me. Lots of options and decisions. That, and I still can not find that system that will work with soup cans and string.