AT&T makes my iPhone purchase SO bittersweet I often regret buying it.
I wouldn't go so far as saying I regret buying my 3GS since it's a vast upgrade from my 1st gen iPhone, but I was rocking T-Mobile on that 1st gen and everything about the carrier was better.... I mean EVERYTHING.
Their network didn't drop calls, the coverage in Chicago was fantastic just about everywhere but basements and their people are an absolute dream to deal with.
Now that I've got AT&T I drop calls constantly, the 3g only works in certain places (and one of the 3g dead zones is right at the Michigan Ave. Apple Store.... It's totally ridiculous... the phone says 3g, but you can't receive data at all.
I wish I could take this beautiful phone to Verizon... no, no... actually! I wish T-Mobile's 3g network was compatible... thats what I really wish...
I miss not being treated like dirt on the bottom of someone's shoe.