I'm not so sure about external batteries, but I suppose that's because I don't know much about them. On the other hand, having to continually buy a new set up because internal batteries tend to be poor doesn't sound too great either.
Personally, I don't really care what the device looks like. I was mostly looking for safety, durability, and longevity. Although having bought an Aspire Zelos kit, I've discovered I very much prefer having a tank to fill with ejuice over the constant hassle of adding it into a cartomizer to keep the cartomizer wet and prevent burning the cotton inside. The tank kindly keeps everything nice and moist for me. *laughs*
I was surprised to find the vapor quite warm, which my Vision Spinner II never produced. I can't quite decide if I like the warmth or not. *laughs* I suppose over so many years, I've gotten used to a cool vape. I'm sure I'll adapt to whatever I settle on since my priorities will always be safety, durability, and longevity. Although, I think my single day with the Aspire Zelos has spoiled me into being attached to tanks as well. I always hated having to fill up a cartomizer then constantly hand feed it and pray I'm paying enough attention to not accidentally burn the cotton. It also sounds as if external battery devices have become much safer over the years if so many people are recommending them.
I'm not particularly sure the true meaning of mouth to lung or air flow yet, so I imagine I'll have to take the time to go through all of those guides to fully grasp the meaning. At least in the meantime, I have something that isn't extremely hard to find, is quite a bit more updated, and less of a hassle when it comes to keeping the cartomizer wet until I truly set my sights on the device that will be my prize for a while.
Back when I started vaping, I had foolishly tried using the devices that looked like cigarettes, had a similar weight and even the tip turned red when you breathed in. To say you could barely get any nicotine out to satisfy your craving and their usage was limited to 200 breaths in, made them quite irritating to say the least. So I cam here for help.
After some advice, I started using the Vision battery series, I started with their very first. Out of all of the ego type batteries, Vision was supposedly the best for safety, durability, and longevity. Not to mention they delivered enough nicotine to actually help me quit smoking. For the most part, they really were everything I'd asked for. Eventually the Vision II came out and it was even better, soon the Vision II spinner, again, better still. Then the Vision III which was a complete let down. It had no longevity what so ever. Usually they died within a week or two. So we just went back to the Vision Spinner II until recently.
I was content not having the top of the line when it was a product I trusted, but suddenly that product was impossible to find and well...here I am. Once again turning to the community that solved my problem with those tiny ecig models that look like actual cigarettes but had no real power behind them and died out fast. *laughs*
So forgive me if I'm considerably behind the times and terminology despite how long I've vaped, but I've trusted you all before and found a perfect fit for probably a decade now. I even ended up a far too loyal costumer of theirs. *giggles* All good things must come to an end, however, so it's time to move on and explore all the advances that have been made. I'm just glad none of these advancements are going to send me back to those pretend cigarette models. *snickers*