I was HATING my old iPhone 3's incredible slowness and dropped calls with ATT. I'm more than a little jazzed about the iPhone 4S, particularly it's speed. (Yes, Siri is tres cool too.) As I was keeping my old phone at a lower iOS, it did very little in terms of multiple apps running simultaneously. You could listen to music, type an email and receive a text all at once.
I believe that with the new iOS, multiple apps can running in the background, but I'm not sure how this affects battery life and processing power. I am most curious about running a 3rd party app to get text messages.
Does an app like this need to be running in the background when you are not texting or does it simply use the same amount of resources that Messages.app would use receiving Push data?
If it uses more resources, is the impact on speed or battery life noticeable?
Any particular apps recommended for Messaging to and from my phone number?
How do you kill an app that you don't want running in the background?
Linked Question: http://www.experts-exchange.com/Apple/Hardware/Q_27402670.html