Jailbreak iPod Touch 4G?

I want to jailbreak my iPod Touch 4th Generation, but I'm not sure which program to use. I tried Greenpois0n on my iPod Touch 2G, but I've also have been looking into jailbreakme.com. Which one is better and why? Tell me which one makes the iPod faster. I think Greenpois0n slowed my other iPod down a little, but I don't really care if I get free apps, but would jailbreakme.com make it less slow? Thanks in advanced! I really appreciate your answers! ;D