I watched the review, and understand the underpowered part (he tested the voltage across a known-resistance coil and found the 213 actually puts out about 155W maximum), though I'm a little curious about his TC review. When he "locks" the resistance in, it clearly says "hold to lock", yet he doesn't hold the button. I'm wondering if that's the cause of his TC issues. The 155W could also be a consequence of the batteries' internal resistance not being accounted for, I'd like to see the tests re-done with a set of HB6's or some other cells to see if it changes.
Not that I'm defending Sigelei, their response was pretty appalling!