How much do you travel internationally? I may have a trip coming up where I'll need to cross the Atlantic. It's nice to have a World Phone. Even though Verizon currently operates on the CDMA network, it has several World Phones that are capable of switching to GSM when you're overseas.
Given that many major medical meetings occur in different countries, it may be a good idea for you to invest in a World Phone if you plan to travel to many of these meetings.