The titanium nib on one of my Ambras is a funny tool.
It is effectively elastic and quite flexible, even if not comparable to the true flex vintage nibs like those produced by Omas until the end of the Sixties.
As RubenDh wrote in another thread, the blade of titanium is pretty thin, and one has often the impression that a joyful pressure could destroy the tines... Until now, however, the Ambra worked flawlessly with its flexible nib in titanium.
The only point I would change in this nib is the basic width. It lays down a wet line more similar to a broad fine, or a skinny medium. If originally grind to an extra-fine tip, it would have shown better its flex properties.
In the Ambra celluloid, the dark brown tones are actually a vivid purple, made darker by the thickness of the material. Where the celluloid is thinner, like in the section, or the lip of the cap, the transparency of the material shows it "true" color. I especially like, in the Ambra, these purple glows that make the pen so vivid.