Windows 7: iPhone 4s

Right now iPhone 4s prices have got quite low and as i am with Orange, i get a free upgrade each year. My 2 options are iPhone 4s for free or iPhone 5 for an extra £135. i know it looks like any person that can read would opt for the 4s but that isnt my question.
I have read that the 4s' CPU was underclocked from 1.0GHz to 800MHz for the battery life to increase. If i were to get a extended batter pack or just simply a bigger battery i could overclock to the A5's base clock of 1.0GHz and maybe get better performance and still the same battery life.

Any opinions

1st. Its your choice, but i wouldn't temper with the iphones settings. Apple designed it uniquely.
2. The 4s, is really fast trust me on that one. It's pretty smooth and quick, unless you have like 70 backround apps running. (which can be closed by double tapping home, and holding your finger on the app then pressing red mark on the app.)
3. If your carrier Orange has 4g , (not sure because i am in America) It will make it a little faster on data, but battery life will be eaten somewhat fast.
4. I would just get it, and if you want to try to make it faster go for it. I suggest getting a case that extends the battery, i think you can find one for about 70 dollars. again sorry, for i know not UK currency, or carrier.

forget about overclocking, it apparently deletes the software restrictor and makes the prcoessor run at 95% of the 1ghz 24/7