If Scarlett Johannson had encrypted the self shot nudes on her phone. The person who hacked her phone and stole them would've had one heck of a time decrypting them to view. It's a nice security feature for whatever you deem sensitive data. It just makes it very difficult to view the file content, aside from the parent device. Given the chipset and ram in the Rezound, it's not gonna slow you down noticeably unless you go haywire and encrypt all your apps, pics files etc.,. Even then I doubt you'd notice anything aside from some extra digits of available ram ticked off when encrypting is in use. As far as it's effectiveness in use is concerned, look at Moto for an example. They encrypted the bootloader on the DX. All efforts at decrypting it have proven futile for every hacker who tried to crack the enigma. So they gave up and ceded to defeat.