I am debating between buying a 5S running 7.1.2 and another one running 8.1. I plan on jailbreaking it but all of my tweaks have not been updated for iOS 8 yet and I'm worried they might never be, not to mention shortcuts and wifi not working on iOS 8. My question is, is there any advantage to a 5S running 8.1 over 7.1.x or will I be fine? Does it run any faster with 7.x? Thanks!