If you want to know WHEN your alarm goes off (because as loud as one can be... it can be silenced in a matter of seconds)... get the model that'll call you when the alarm has been triggered. This way, you know WHEN the alarm has been triggered and can act accordingly... What's accordingly? Guns-a-blazin' out the front door? No... I mean, calling the cops to let them know your truck is driving down the road without you in it.
...I also have the GPS with my alarm. I can log in (via my phone or any computer) and not only activate the kill switch (so the vehicle won't re-start), but track the vehicle and know it's whereabouts at any given time. Unbeknownst to the thieves, a LEO can be informed of where the truck is... or which road it's driving along. Simple, yet very effective.
AND, installed with solder/heat shrink... the only way to do it, by my buddy Kenny who owns Soundelux Car Audio;
https://vimeo.com/38154934
The is a clean unit (newer then mine), that does what it should;
http://www.google.com/products/catal...d=0CJkBEPMCMAM