I won’t take the easy way and out say, it depends, but the bottom line is that you’ll pay $25 more for the Verizon iPhone than the AT&T model for similar services.
You’ll receive unlimited minutes, unlimited text messages, unlimited data (Verizon) or 2GB of data per month (AT&T) all for about the same price; the real difference is that Verizon will let you use your iPhone as a WiFi hotspot for another $25.
That’s cheaper than what it would cost you to purchase a MiFi portable hotspot or comparable device where you can expect another $60 per month bill.
So, what I guess I’m saying is the Verizon phone is the better value at $140 per month. The crazy thing is, that’s still a lot of money so if you get one of these things–use it and use it well.