Re-read the post. It allows you to get a consistent vape using different resistances. A 1.5 ohm coil is not going to vape the same as a 3 ohm coil on the same voltage setting. On the same wattage setting it will ... because the device automatically lowers or raises the voltage based on the resistance of the coil.
I did not find this to be the case for me. Switching from a carto tank, to a Vivi nova, to a genesis required watt changes to get to my happy spot, yes it is easy to quickly change power settings with the Vamo, but I found it was too easy at times and would bump the power up or down buttons enough for it to be inconvenient. For me a way to lock the output would have been a nice feature.
One of the other things I don't like about the Vamo is the size, it is about the same size with an 18350 as a Provari with an 18490.