S off means security off...
See
http://forum.xda-developers.com/showthread.php?t=1786498
This is what you can do with soff
You can resize your system partition change radio IMG s get permanent root relock boot loader and make it appear as locked instead of relocked change the splash screen among many many other benefits
Disadvantage turn your phone into a permanently dead brick.
S on doesn't cause major bricks at least none have been reported till nnow on our phone.. It causes bootloops at the max.
Sent from my HTC Explorer A310e using xda app-developers app