Prior to recent developments in home security technology, hard-wired or landline-based systems were considered preferable to wireless systems because they were more difficult to tamper with or disarm. But wireless communication protocols have become much more sophisticated in the past few years, to the point where they are just as or more reliable than hard-wired systems. For example, most modern wifi- or cellular-based sensors test their communication to the central hub regularly — once every hour — to ensure the system is not faulty or being interrupted. Some security companies offer both communication types in the same system as a redundancy.
The real question to ask is whether you want your security provider to drill and run wires throughout your home. If you plan on staying in your home for a prolonged period, a hard-wired system might be preferable; but if you rent or plan on moving, a wireless system will prove much more portable and easy to install in your new home.