I would steer you away from the iphones
4s because it has battery drainage problems:
http://www.techieinsider.com/news/13863/battery-drain-problems-continue/
Even Steve Wozniak, co-founder of apple says the same thing and that siri is glitchy:
http://www.cbsnews.com/8301-205_162-57360045/apple-co-founder-gripes-about-iphone/
And this is an Apple Legend saying this so you know it has to be bad.
the 4 drops calls and is not recommended by Consumer Reports:
http://www.pcworld.com/article/200924/consumer_reports_throws_iphone_4_under_the_bus.html
Furthermore, with iphone you do not get Adobe Flash which is required to view videos on many websites, it is a common complaint among iphone users. Plus you cannot expand memory with iphone if you run out of space but with android you just add a card up to 32gb and you're good to go.
You get more free apps with android, for example angry birds is free with android whereas you have to buy it with apple, or use their "free" version which has a big ad blocking part of the screen getting in the way of gameplay.
Android phones are usually superior in technical specs, faster and more customizable. It is the smarter choice, that is why it leads the global market in smartphones today even with apple selling a lot of their iphones cheap or free.
And despite the Woz saying iphones are easier to use, ANYONE can use android, he had to say SOMETHING nice about apple lol.