Neat and impressive. Its bit difficult to estimate the scale from the video, anyone venture a guess how big this thing is?

It's interesting that even the balance spring appears to be printed, I would not have guessed that to be feasible. In watches custom speciality alloys are used to get the performance needed, and afaik it is also one of the bigger contributors to the accuracy of the whole movement.

Which brings to the big question, how well does this tourbillion actually perform? I get that it probably is intended as a show piece rather than practical timekeeping, but still it would be nice for understanding the state of 3d printing.

Beyond accuracy other interesting "metrics" would be friction/energy efficiency and longevity.