The Joye eGo (branded 'Tornado' by Totally Wicked) is 3.2V. Some other eGo-type fat batts are different voltages, e.g., the Lea is 3.5V and the Riva-510 is 3.7V. [It is my understanding that the
batteries in Liberty-Flight's "Lite Bundle" are
throttled (no more than) 3.7V, whereas those in the "Special Edition" kit are
true 3.7V (i.e., 4.2V fully charged, although less than that under load).]
None of these are necessarily better or worse than others. It depends on the resistance of the atomizer or cartomizer you are using. For example,
I prefer using the dual coil cartomizers on 3.7V (or higher), but the 3.2V eGo is perfect (for
me) with the 1.7 ohm single coils.