I'm updating right now, I really hope it improves my iPod (5's) battery life, because it barely lasts 4 hours of use without charging :/

Some app colours are less vibrant

The Touch ID is much faster now, which was a major issue for me but it's working better now. I also like the Phone app modifications.

It's a lot faster now
The keyboard also has a bolder font, which is clearer

Yes. My 5S got so much faster.

here is the UI changes if you all wondering: http://9to5mac.com/2014/03/10/apple-...-options-more/

and definitely not upgrading I love my jailbroken iphone