There are so many books for "dummies", I will start this thread for ARC Patrol (present company excluded).
I have a HP 1 and can you enlighten me as to when the included sentinel software will not be suffcient and I should consider getting he extreme update and/or ARC Patrol? Thanks.
It would be difficult for others to decide when - or if - the Sentinel software would not be sufficient for your particular needs or interests.
As far as the Extreme Upgrade, that's something you'll have to decide for yourself. The link below lists the features of the upgrade... you can read them over and make your own decision as to whether those features are worth the extra cost to you. Many people find the upgrade worth every cent, and many don't see any value in it at all.
Pretty much the same with ARCPatrol.... you can read about all of the features of that software at the link below, and it also has a 30 day free trial period. You can download it, use it, and compare it to Sentinel and see for yourself if it offers you anything that you like.
One thing ARC Patrol does offer that Sentinel does not, is virtual control of the Home Patrol on your computer. But that feature does require that you have already purchased the Extreme Upgrade from Uniden (to enable serial output).