Several years ago, I was "forced" to let go of this timepiece to fund a dream watch I had wanted.
The Glashutte Original Senator Perpetual is one of the most affordable perpetual calendars around and the fact that they have windows instead of sub-dials made it a lot more attractive - at least to me.
An automatic piece in steel, this is a Limited Edition piece for the US market. It houses the Calibre 39 an in-house movement. If I recall correctly, it was limited to 200 pieces in steel. The platinum has a blue dial and limited to 100 pieces.
If another one would come by again, I'd GO for it. And this time, I won't let GO.