What the difference is in the Ruyan, Super and Mini Cigarettes?

Can you tell me what the difference is in the Ruyan, Super and Mini Cigarettes? Does the cartridges or batteries last any longer in one or the other. I have a black mini and I seem to be going through two or three cartridges a day? The cartridges seem to lose their strength after only a few puffs and then I have to puff real hard or double puff to get a good drag? I am smoking the #3 mediums cartridges. If I got full flavored cartridges would I be able to puff a little lighter and have the cartridges last a little longer? Can you please help me here to learn what is best for me using the e-cigarette? Ilove it, but the way I am going through cartridges I might as well go the cheaper way and smoke real cigarettes. Thank you!