Coming from a 4s owner I feel that's worth it, altough I'm the kind of guy who likes to have the newest stuff. But I love the feel of it in my hand compare to the 4s.
From the 4 to the 5 it's a very noticeable upgrade, even the weight ( or lack there of ) is ridiculously noticeable and has a better feel in my pocket ( though I do find myself check to see if it's actually there more often LOL ).
My wife is in absolute love with her 5 and wouldn't go back to a 4 or 4S if she were paid ( unless it was a substantial sum of money to where she could then go buy herself a 5 again and shoes, a purse and outfit to match ).
I went from a 8 gb iPhone 4 to a 16 gb iPhone 5. My poor phone was on its last little leg anyways, it was time to upgrade and the speed is what sold me. I didnt realize what I was getting into until I had my phone though. The speed is amazing. The battery is eh about the same as my iPhone 4 bc I leave more of the extra stuff on (location services and wifi) mainly. I also had the habit of turning off the 3g bc really I didnt use the phone off wifi much. Now that I dont have wifi at home its been quite the lifesaver!
My 4S had become real slow and it would respring constantly. Even when the jailbreak was taken off. So yes my switch was well worth it. Plus I've been waiting for lte for a while. My iPad had it but not my phone (O_O). That was a problem!
Unquestionably happy...this thing is superior to the 4S in almost every way (not to say the 4S was a bad phone, besides this phone, it would be the phone i would prefer).
I knew it was going to be a big jump from my 4 to my 5. I heard it would be faster then my 4. But wow, I am amazed by the speed that the 5 has. Just for that I am glad I upgraded, and the crispness of the display is great.