Let's share my story...
Back when I first wanted an anti-theft app I went out and compared the alternatives. At that time, I thought Avast had the greatest set of features available and after days of use and exploration, I was in love. I helped out by filing a few bugs that Reinhard Holzner kindly fixed in a quick manner. And best of all, it was free. I would even pay 5 bucks for it on the Play Store if that was the price. However, here's the problem. The only security feature I care about is anti-theft, no backup, no antivirus, no other. Paying 2 bucks a month for the extra features however will never going to happen in my case. I still think Avast Anti-Theft is one of the top anti-theft apps out there but the competition is strong. Since I'm not ready signing up for a subscription payment only for anti-theft, I'll happily move over to Cerberus and pay me into the premium features for only 3 dollars (one time payment). Before I uninstall Avast Anti-theft however, I want to thank Reinhard for his help and development for the app and the community of course.
I also want to report a minor bug with the beta release: When remotely taking pictures, the shot-sound will be heard. You should extend the time the device is muted in order to completely remove the sound. It's probably completely removed on other ROMs and phones, but on my Nexus 4 running CyanogenMod 10.1 (Android 4.2.2), the shot sounds. If it's possible, you could maybe remove the notification icon indicating the phone has gone into silent mode and immediately exited it.
Thanks for your time! Hopefully Cerberus is as great as Avast Anti-theft.