Bear in mind: if you get the unlimited texting plan, then you can get unlimited calling to any US mobile phone (regardless of network) included at no additional charge. Plus, you'll have 1500 night/weekend minutes.
I text more than I talk, but I still use about 1,000 minutes a month. Even so, I'm on the 450 minute plan because 90% of my calls are to other cell numbers. So, not only am I still well within the plan, but I'm even backing hundreds of rollover minutes every month.
Those rollover minutes can come in handy by the way. Once I did have to set up a lengthy conference call for work with 4 other phone lines, and the easiest way to do it ended up being on my iPhone (which on AT&T can conference up to 5 people in a call at once). That month I did blow away my 450 minutes, but I had thousands of rollover minutes that easily covered the overage.