I like the 5711 for its simplicity, and its allegiance to the original model that debuted in 1972.
However, the 5712 does speak to me as well; although I don't like the overall idea of the moonphase, date, power reserve, and small seconds (I think this is a strange combination); I do find the overall layout very readable and very beautiful. Furthermore, the beautiful caliber 240 movement makes the 5712 even more enticing.
I couldn't tell you which one to choose, but I think I'm currently leaning slightly more towards the 5712 even though that I don't like the philosophical idea about the display on the watch. But I'm a caliber 240 lover.
However, one cannot possibly go wrong with the 5711. Personally, I'd consider acquiring both of them.
Good luck PinkPanther!