Just JB and find out yourself. Any person who says the JB has bricked their iPhone or has noticed battery drainage issues or even crashes is a freaking re-tard. 🙄
The people who have these issues are always the kids that try to be cool and JB and do not know what their doing.
I have jailbroken for the first time on the 4S and guess what? No issues at all! The only issue I had was trying to figure out how to respring. 😕 Which I now feel stupid for not knowing how..