Those are induction heater irons, something like a temperature controlled Metcal but at a much lower frequency and no curie point tips.
Ok that makes sense now. The tip fits very loosely but it does heat up fast.
It's a 160W station and I can get close to the power limit when soldering big copper plates, so it looks like T12 wouldn't have done the job.
I'm not convinced that the more expensive cartridge based stations offer much improvement over this, so for now I'll conclude that around $50 is the sweet spot for soldering stations if you spend the effort finding the right one (in china at least).
In the future if I need more thermal performance I'll look for induction heating soldering stations using tips with a bigger stem diameter, as this is the final bottleneck to thermal conduction. There is probably good reason all the soldering stations marketed for "high rate" use (production use) here are now all induction based.