I don't know that it's evolved so much... I did go from a Type A to a Type B tank, but otherwise...
However, I did go from an 808 to an eGo to a Provari and then back to an eGo... The USB PT eGo seems to last longer than the Provari with an 18650 battery, and I tend to keep the Provari around 3.7 anyway with an lr atty. I find that I'm using the eGo more and more, and the Provari less and less. Still glad I have one, but the eGo is lighter, simpler, and does just as good of a job...
Does that count? eGo got bigger (1000 mah), and got a USB port, tank grew, and it suddenly found its way back into daily use...
However, I did go from an 808 to an eGo to a Provari and then back to an eGo... The USB PT eGo seems to last longer than the Provari with an 18650 battery, and I tend to keep the Provari around 3.7 anyway with an lr atty. I find that I'm using the eGo more and more, and the Provari less and less. Still glad I have one, but the eGo is lighter, simpler, and does just as good of a job...
Does that count? eGo got bigger (1000 mah), and got a USB port, tank grew, and it suddenly found its way back into daily use...