I honestly don't really care, as long as it can call and text everything on top of that is just a bonus. If it wasn't for the Twitter app on my Blackberry I wouldn't use it for much outside of texting and calling people.
i'd suggest that you not waste your money on an new iphone or an android, if all that you want is calling and texting. you can get a cheap, or even free, phone that will allow you to do that.
you can even get a free iphone 3 when you re-up. doesn't sound like you need version 4, so why pay $200 or more for it?