I can also turn on speaker phone, and go into say maps or open up Safari to check something out while still talking
That's nice in theory, but I can count on zero hands how often I've EVER needed to do that. I don't even make phone calls with my phone, to be quite honest. Once a day during the week to tell my coworker that I'm picking him up, that's about it. Besides, I can multitask just fine with speakerphone and offline apps, which is enough to take notes. If you're going to be dicking around online during a phonecall, you're probably just wasting minutes anyway. It's a feature that you'd rather have than not, but hardly a factor - much less a dealbreaker - for most people.
We can go back and forth about carriers all day, but my experience with Verizon has been great, and I would not risk my satisfaction with another carrier for one device, especially with all the bad things I've heard about AT&T - a sentiment that many share. Now that the iPhone is no longer exclusive, people don't have to "take it or leave it".
In short: Choice is ALWAYS good. Now what are we arguing about again?