Some of the previous VZ global phones clearly stated that in Global mode, GSM was searched only if no CDMA signal was found. Can't see such as a statement with this phone. Anyone know if that's what it does? (In which case Global and CDMA are about equivalent in areas with strong CDMA)Global mode has it searching for both CDMA and GSM networks. If you're using it in the US, you can only use CDMA, so you might as well set it to CDMA, it'll save you battery life. Just remember to switch it back if you intend to travel overseas with the phone.
As long as you have nationwide roaming, I would assume automatic. That's what mine's on.