because of the fascinating little machinery and mechanics of building this into a wrist watch.
After seeing so many watch makers able to do so and even producing sub-$15K perpetual calendars, from Mont Blanc and JLC (no offense, both are reputable brands), I asked myself ....do I really need one?
Indeed the 5726/1A and 5711/1A was a bold step, and it's more expensive than many precious metal watches and other brand's perpetual calendars.
Having said that, it is a Patek....and no watch collection is complete without a Patek.
The Nautilus polish and finishes are superb, very high quality.
The white dial, imho, is very legible and the contrast is good. I see myself wearing this for many years and when I'm old, I'll still be able to read the dial.
Eventually, I also see myself buying a traditional Patek, with grand complications.
Rgds
Raymond