I can leave short note after years of use.
I managed to almost fry the motherboard of the first one. Charging stopped working, but I could still use it with external batter charger. I was impressed that it just did not die, but kept on going.
Definitely do recommend the glass mouthpiece. Its not perfect, but far better than plastic mouthpiece. Silicone do wear out after 2 years of use for me, I do remove the metal insert and use vape mesh as the screen instead. Between glass piece and silicone. With that config also 3x glass dynavap screens as inserts comes handy to put it between the herb and screen. Gives me better performance and its easier to keep it clean.
I was checking the portable vapes for the upgrade, and its not easy if you keep in mind my priorities. Resonable price, glass mouthpiece, removable battery. 26650 cell, fast charging, less silicone in the mouthpiece and I would be happy. So what about v4 pro : P