The one Pico I have in service has recently been occaisionally dropping out of TC mode into power mode. May be my higher resistance builds are pushing a safety feature on the board. My vtc mini, only recently,, has been asking if there is a new coil or old coil for no apparent reason. These behaviors are a minor annoyance that I'm only paying close attention to because I might be dependent on my supply of those two devices for years to come. In general I think the chinese are very good at engineering and machining small parts. Having said that it was an american company, evolv, who came up with both watts and temp control. But having said that, it was a chinese guy who invented the modern electronic cigarette. If I could meet and talk to any person alive today it would be Han Lic.