Having read through this thread I have to confess surprise at some posts and dismay at one or two of the others. I can't offer a fix or cure all but can only relate to my own personal experiences. Folk can then make up their own minds and decide from there.
Firstly and not as a boast but just to let you know I am not just a recent convert, I have been vaping for longer than four years now and have come through the ranks, like many have, of cigalikes, eGos, regulated devices, mods, coil building and juice mixing etc..
During that time I often built coils that were below the 1.2 ohms acceptable to a Vamo and simply put them on one of my eGos and vaped away without issue and without any more undue thought.
So having read through this thread and wondered at some of the theories being put forward I have just taken a Russian 91% with a 1.2 ohm single coil in it, put it on my 2 and a 1/2 year old eGo and vaped away no problem. Then I took a Fogger V4 with a 0.9 ohm dual coil, put that on the same eGo and vaped on that without issue. Much as I have done since buying the eGo.
I have three eGos. The original I bought has a black button and the circular Joyetech logo on the bottom whilst the other two I own have a white or clear button and no logo on the bottom. These two are over 12 months old and these again have given me no cause for concern.
Joyetech logo:
Over here in the UK over the last 18 months or so, we have been flooded by so called e-cig shops popping up on most main streets, street markets and what we call boot sales or markets. Where someone rents a field for the day and then any Tom, .... or Gilbert can just turn up, pay a nominal fee and sell whatever they like from the boot/trunk of their car. Completely unregulated although now more closely scrutinised by the police and customs people as being a known outlet for stolen or counterfeit goods. Sad to say though vaping supplies gets past the police scrutiny as officialdom has little or no knowledge of vaping supplies.
All the outlets mentioned above have been selling cheap blister packs of supposed eGos, made in back street Chinese sweat shops and in many reported cases have had very poor PCBs inside, inferior wiring and in a number of instances, fitted with fraudulent batteries. By this I mean the device was sold as a 1100mAh device and when opened after repeated claims of only last an hour or so, they were found to contain something like a much smaller 290mAh battery and the remaining space in the tube was filled with a piece of foam to stop any rattle or pulling of the wiring on the PCB.
How many of these devices entered the UK? Nobody knows but they entered the UK by the container load and it's anyone's guess as to how many blister packs you can get into just one shipping container. How many have been imported into the US?
As I have previously said, I cannot provide a surefire answer to folks issues mentioned in this thread but possibly point some toward what might be a problem solver by way of a new coil that is handmade by a UK vaper who has recently started his own business and at the moment looks to provide a game changer in pre-made dual coil vaping.
I will stress that at this present moment I have no connection with this company and have not even used them but I will be giving him my custom in the very near future based on a couple of reviews I have seen. One of those reviews was by Todds Reviews whose opinion I value highly and the other by Martyn Parker, a newer reviewer. Have a look and see what you think. It might just help some.