Just adding my experience. Bought one of these T320 units with the T245 handle and 3 tips. It was quite the joy to use. But it went totally dead after ~2 weeks. Power supply was dead. No obvious component failures. The design is very serviceable, so I contacted the seller (Bresunfix) to get a new power supply board and they asked me to take a video of it not working (here: ) and make it public so you all can enjoy it. They said they would elevate the issue and contact me within 3 days. When I heard nothing, I again contacted them. They were very apologetic and said again that they would get back to me in 3 days. Again nothing. Did it one last time, and again nothing. I then tried contacting Aixun directly to get a new power supply board. ZERO response. Finally, because it was a "Choice" purchase, I was able to return it through AliExpress at their expense. They have received it, but said they need to process it before they can refund my money. So that's where things stand.
While it was working, I ordered some chisel tips which I vastly prefer. Now I have tips, but no iron. Given the generally positive reviews, I think I will order another (with "Choice") and hope for a better result.