I agree, there are several attys and
mods currently on the market that work very well, however most of them use some design or concept that would have been patented if patents were wide spread in e-cigs. Look at the carto, if the original maker patented that design, how many items today might not have ever been made, and how many of those new item lead to other changes? I also don't think the patent for VW is just as their chip does not actually control wattage, it controls voltage to give you a wattage close to that which you want. For instance, take a 1.8ohm coil. You want 14.3 watts, ever notice the voltage stays the same at 5VDC from 13.9watts to 14.4watts. To say you actually control wattage you would need a more accurate delivery of voltage beyond 0.1. This is why VW power supplies are so costly, some control voltage down to 0.0001 volts. Evolve is simply displaying an approximate wattage based on voltage and resistance.... not truly controlling it.