My iPhone works ok on our westward facing lanai but in the house it's risky to move once a call is established. The AT&T signal where I'm sitting now is 4 bars and 3G, but I can't take a call here and expect to walk inside.
So plan to use your iPhone only on nice days if you're moving to this beautiful neighborhood. Maybe the iPad will have a more sensitive receiver?
Edit: the portable landline phones do the job everywhere and WiFi is good, too, for the iPhone. Pay fees to everybody that comes along and you'll be always connected. :-(