I don't think you have to go to a fat battery model like Ego unless your need 6-8 hour battery life and the option of hotter bigger hits with LR (low resistance) atomizers and cartomizers. I do think you need to step up to one of the basic models - 510 or KR808D-1.....
I can't agree with this point because the OP has already tried two small battery devices and has been disappointed.
And better battery devices are NOT just about the length of time between charges. More important is that better battery devices provide more consistent, warmer vapor for a longer period of time because they hold a full or near full charge longer which is required for optimum atomizer performance. Thus the user has a better, more consistent vaping experience!
I do agree that LR attys can improve the vape of a small PV and is a better option than the OP's current set-up. But I have not found them to be on the same level as a better battery device. I also have read that their failure rate is higher than standard atomizers and it also limites to a degree which atomizers one can use. And of course it does not address the continued need to change batteries every hour or so.
If someone has never used a better battery PV, especially a 5 volt or variable volt PV, there is no way they will understand the difference. I've personally seen regular 510 users try a variable volt PV and state that it was like they had not vaped before because the warmth and consistency of the vapor was so much better.
And I will apolgize up front if this is being "picky" but calling an eGo a "fat" body PV is just misleading to a newbie and could scare them into thinking it will be the size of a full size flashlight when at best it is the size of a slim cigar.
Most new users are looking for ease of use, consistency and the "inhaled feel" of an analog and do not understand (understandably so) that you will not get that in a "mini". The OP is frustrated with how much money they spent on two mini PV's and is still not happy. Leading them to another smaller PV may just lead to more frustration.