At Stepcase Lifehack, the article Home Automation: Evaluating the Options offers an overview of the differences between wired and "plug-in" automation systems.

It's a good piece, but I'd caution that it understates, by omission, the difference in costs. Hard-wired systems start at approximately $10,000. So simply stating that they're "more expensive" is as much as an understatement as saying that plug-in systems require "landlord's approval" is a misstatement. (The latter is simply not true, no permanent modifications to your home are necessary.)

The earlier article in this series, Home Automation: What It Can Do For You is commendable for describing what you might want to accomplish, and I'm looking forward to the rest of the series.