Having not actually used every battery type out there, I can't give you a definite answer. I will say that since analog sized
batteries are all about the same size, that they will probably all give you about the same amount of
vaping time before recharging.
I think most vapers probably start out wanting something that looks like an analog. I personally couldn't handle the constant recharging and having to carry extra
batteries everywhere. So I gave the eGo a try. I figured the size would deter me from carrying it around and using it in public, but I discovered it's not really that big. I don't hold it like a regular cigarette, but it was very easy to adapt to. Now when I use my old analog size 510 it feels funny...too lightweight.
I'm sure others will give you their opinions of the smaller style batteries they've used, but if you've already discovered that battery life is important to you then I suggest you consider giving an eGo or Riva style unit a try. The cool thing about the eGo is that many of the accessories you use with them (cartos, atties, etc.) are interchangeable with the smaller 510 battery.