Check to see LTE coverage area and speed. I know AT&T has LTE in my area, but I'm not sure how it is where I live, work etc.
Also I am excited to see if the updates to siri make it more efficient to use on a day basis.
My issue with Siri previously is that it made it take longer to do just about everything. It was easier to just pop open safari and google something or to just manually enter things into the calendar than it was to try and say it siri. But it seems like that may have been improved on.