Whereas I've been quite close to buying the 33155, which feels incredible on the wrist and which has such a beautiful movement.
So, between the two, my personal choice would be the Ultra-Thin 1955, without the slightest hesitation.
To be perfectly honest I have add one thing concerning the Ultra-Thin: I'm not completely fond of the indexes, which are neither applied nor painted. Masks that match the shape of the hour markers are applied to the raw dial base and, once the surface treatment is complete, the masks are removed and the hour markers are polished. It's a very innovative technique, but the indexes feel a bit flat. I personally prefer the applied indexes of the original ultra-thin model ref. 6099.
So that you can get a sense of how these watches wear on my wrist here are some photos (in fact, screenshots of videos I took at the time). And I have added a photo from Hodinkee of the indexes and a photo from Antiquorum of the ref. 6099.
Hopefully, it will be helpful.
Best, Emmanuel
THE 81180
THE 33155
THE "POLISHED" INDEXES OF THE 33155
THE APPLIED INDEXES OF THE 6099