There is no universal answer to this, as it all depends on your property and circumstances. Here are some things to consider when choosing which system to get:
While wireless systems usually cost more to buy, they are much quicker to install which will reduce the installation cost. Wireless systems will also incur higher running costs as the batteries in the control panel and devices will need to be replaced periodically.
Wireless systems cause less aesthetic disruption to properties, as no cables or trunking are required.
It is usually easier to expand wireless systems by adding on additional devices. It can be far more complicated with wired systems.
It is much easier to take a wireless system with you if you move. While it is possible to disconnect a wired system and re-cable it at the new property, it would be time-consuming and costly.
Wired systems generally tend to last longer than wireless.