For many users, the Verizon iPhone is a big step-up from AT&T when it comes to quality service. Service on Verizon is simply more dependable: calls don’t drop as much, the person you’re speaking to seems clearer, etc. That’s 95% of what most people care about.
That’s not to say the Verizon iPhone’s a slam dunk for everyone, though. It has its drawbacks. Verizon’s CDMA network can’t handle the simultaneous juggling of data and voice. 3G speeds are inferior to AT&T’s. And, if you’re a business user, the Verizon iPhone has some serious limitations when it comes to conference calling: not only are you limited to conference calls with just two other people, but you can’t switch between conference calls either.
These aren’t problems with the hardware: just limitations with Verizon’s CDMA network, and ones that every Verizon user has to deal with. This isn’t likely to be an issue for more than a small percentile of customers, but if you’re one of them, and need your network to handle conferencing robustly, you might want to think twice before making the switch.