Apple iPhone 4 (CDMA)

Manuafacturer's claims for battery power are calculated based on power draw and battery capacity - and are not based on actual long term use in actual locations. Anyone who has owned several phones knows these talk/standby don't have much bearing on real life, use of phone and typical usage.

While the power used by the RF sections may be roughly the same in a lab, it is how they operate in use, seeking signals from towers and power used for standby that makes a difference. All else being equal, CDMA usually uses more power per minute of voice call talk time vs GSM. Most CDMA phones will drain the battery far faster in low or no reception areas even if no calls are made.

What is not yet known or published is what changes or tweaks Apple has made to the CDMA model - talk time is equal but since Apple seals the units, they may have a slightly larger capacity battery. Someone will undoubtedly crack theirs open next week and publish the results. As I said, Apple is the master at maximizing battery life in their hardware, and few other phone manufacturers dare make their phones with sealed batteries.

Another factor is data use. GSM phones use WCDMA which, while not compatible with CDMA, is related as far as basic RF operation is concerned, so that equalizes the experience by users with each technology.