Jailbreak

Whether to jailbreak an iDevice or not, all is your own choice.
The importance is on whether why are you doing that. Are you jailbreaking your device to enable certain 'additional' function for your device. Making it more interesting like having lock info / themes and much more.
While some of them, the main point of jailbreaking their iDevice, is for installing those cracked apps only.
A friend of mine, using an iPad. The only thing she did after jailbreaking it is to download paid apps for free. Which means illegal.
To jailbreak an iDevice, by means hacking it, open up the holes in iOS which enable certain function of the iDevice which Apple don't allows us, the user to use. They claim that those function will be shorten the lifespan of the device and hence, was blocked.
So, think before jailbreaking your device.