as much as I can understand the desire of "categorizing" all and everything, I've to admit that I find it largely misleading in most if not all cases.
Staying "on topic", continuous ves. semi instantaneous vs. "true" instantaneous minute counter design:
Using terms like "classic design" should happen only within a certain context, IMO. Simply putting it the way you tried, it's misleading in my oppinion. Many very fine movements of the past, among those many from highly regarded "top houses" and movement manufacturers in some cases had continuous minute counter designs. At the same time it would of course be correct to say that at a certain time the semi instantaneous minute counter was considered some sort of "industry standard". In fact traditionally speaking there was a large variety of minute counter designs, and among any specific group more or less sophisticated versions of course.
"Departing from classical design" ? No, way Almost any known design has it's traditional predecessors and could be considered "classic". Maybe continuous running minute counter could even be more "classic" - I think it may even be the older design.
- "Easier to build"?
Again, there are almost infinite ways to go within any specific "group" of designs and attributing something like "vastly easier to build" with one specific "group" of designs is oversimplifying and thus misleading.
There are incredibly simple semi instantaneous minute counters as there are relatively straight forward and simple continuous running minute counters. It simply depends how it's realized.
- "Easier to design"
As said, historically there are very simple designs of both groups. I'd guess if one would think about a competition of the "most simple design possible" and you'd exclude central minute counters - maybe semi intsantaneous would even be the more simple solution (especially taking intoaccount possible tolerances for production).
In some cases even the true instantaneous minute counter can be the "easier to design and build" solution (in cases it would have to be added to an existing base movement for example)!
Coming back to your initial comment and comparison between the Piguet cal. 1185 and Patek Phlippe's cal 28-520:
"And as I was carrying a copy of the Patek movement (the 5960 chrono base) it was easy to see how much more simple the design is."
And earlier, in the thread which started this discussion:
"Second, take Blancpain's more sophisticated jumping minute counter and substitute a cheaper constant running minute counter."
I've to admit that I'm at a total loss here and I seriously can't believe you're serious here
Here's an exploded view of the Patek minute counter part:
As always I remain open to any other oppinion, view or correction, but in this case I would even disagree with A.L. Breguet personally (if he'd make that point, what I actually don't believe
Any single part in the Patek design is, more complex, harder to produce and most likely more expensive.
I don't have a good picture or even exploded view of the Piguet movement at hand, perhaps you've one? That certainly would help the larger community to understand the difference.
I sincerely hope we'd be able to sort out the technical aspects from the rethorical ones - it certainly would help to understand.