I went from 4s to 5. i wasn't going to upgrade at first, then changed my mind when i tried the iphone 5 at the apple store.
I love the bigger and nicer looking screen (i watch movies on it, on the go). Movies are widescreen now. Some people use ipads but i'm happy with iphone and mbp.
it is quicker than my 4s.
I don't have LTE yet, coming this summer on my carrier. Iphone 5 has higher fps on some games etc...
I don't update my mac often and don't need an ipad but the iphone is the only gadget i like to have up to date...