There are also the operational and electrical considerations.
The Liquidator is a purely mechanical device that works with the laws of physics and chemistry, you can trouble-shoot it by eye ( full/empty, flow/no-flow, etc...) and it can be connected with-out cutting your plumbing.
Adjusting the flow-rate knob is your only setting. You only need add liquid chlorine (Bleach, 10%LC, 12%LC, etc..)
An electronic chlorine generator will require an electrical connection, in addition to physically cutting the plumbing. The programming can range from a simple time or % setting, to much more complex. If you have trouble with electronic devices, it may prove daunting. Trouble-shooting is more complex because of the flow detector and other electronic measurement elements. You will need to add salt initially, and probably muriatic acid weekly, if your ph creeps up, (although adding borates can combat that.)
Both will need to be cleaned (with muriatic acid) and inspected periodically, your pool chemistry and habits will determine how often.
The liquidator will be much cheaper to purchase, operate and maintain, but still requires the hauling of chlorine containers, which is what you have to weigh against the convenience (and costs) of electronic chlorine generation.