patrick_y[PuristSPro Moderator]
33528
Great technical question!
Welcome to the site!
We have some superb qualitative and technical answers by some of the other members of the forum.
I too personally like the design of the 5197 more, but I do agree the 5177's caliber is the more desirable caliber.
Considering that you want an automatic caliber, have you considered the 5140 (another forum member recommended this already).
Pros: It is beautifully thin, automatic, looks great, has a small seconds subdial (which I prefer due to the large seconds creating too much movement on the dial), comes in both guilloche dial and enamel dial. Reasonable 46-hour power reserve. Big watch, very legible and great 40mm size.
Cons: It doesn't have date, it has a nicely finished movement, but the movement is not visible through the back, solid gold case-back.
Here's another post about the Breguet 5140 from 2008.
Keep us informed of which one you get!