At&t is the best carrier around my parts. I've tried the rest and there were massive holes in their networks. Verizons especially. you MIGHT be able to get a call outside somewhere but walk in a building and it went away. Since I went to ATT I haven't found a place where it doesn't work. Even in our local supermarket which normally you think it wouldn't (lots of concrete and steel).
As for the iphone, say what you want about it but it's a good device and cheap if you get it with a contract. I've had mine for ahwile. And being disabled it is a huge help for me. I can now read books without getting migraines because I can adjust the type. I can bring my bible and bible study materials with me anywhere and I didn't pay a cent for them. Nice to be able to read a scripture and look up meaning of words. I can view any bible version i could think of also. Or listen to an audio bible, all for free. I have problems sleeping due to pain, they have white noise generators like waves that help with that. I can track my sleep patterns to report them to my doctor. I can track what I eat so I know what makes me ill (serious problem with my disease).
I could name a dozen reasons my iphone helps me have a better quality of life. I understand most people don't have the needs I have or a reason like mine to have a device like this. Not saying an iphone alone wouldn't do it, but if your hung up on the droid being the end all device, it's not really that different then an iphone.