You are an idiot if you think the jailbreak will work perfectly on first release.
It's a program that modifies a stable software, exploits it, removes core files, disables security functions, and you expect it to work on first release? No, just no O__o
Evasi0n 1.4 works great.
My personal iPhone 4 is on 5.1.1, but 4S is on iOS 6.1.2
iOS and iDevices are my life.