Well...In term of complication, an annual calender chronograph is miuch more technically important than a simple annual calender...
In the brand, you have 4 kinds of annual calender: 5146; 5396; 5726 as well as 5250...
but there is only one 5960!
In fact, I will rate 5960 as one of the most undervalued Pateks today...5960 hands down absolutely!
Just MHO



