Gryphon 500A Car Alarm for 2011 Prius ????

I am considering an alarm for my 2011 Prius III, and wanted to know if anyone's heard of Gryphon Car Alarm, specifically model 500A, and if they have had any issues with it or recommend going with another car alarm. I want to install an alarm on the Prius, but don't want to go through a nightmare doing it. Hoping to learn from everyone's experiences.
Please let me know your thoughts. Thanks in advance.