In large part, this is a matter of taste and style rather than objective facts. Obviously, comparing them both in the same metal and both on bracelets we have two 12-hour, 3-subdial chronographs with screw down crowns and pushers, and a good case could be made for selecting either one.
Some differences that might matter to some buyers, one way or the other, are:
The Daytona is apparently produced in much larger numbers and is recognizable to many more non-WIS. To some this, is a plus, to others a minus.
The Daytona is 40 mm; the newer Overseas Chrono. is 42 mm. Some prefer one over the other.
The Daytona now uses an in-house movement; the Overseas Chrono. uses a modified F. Piguet movement. Both are fine and plenty accurate, but some people care about whether the movement was made by the same company that owns the brand name.
Daytona models vary in the legibility of the time and subdial counters to a greater degree than Overseas Chrono. models. Some people care about being able to read the time or elapsed time, others not so much.
The Daytona has no date, while the Overseas has a large date (but not a very readable one to my eyes). Some people care about a date.
The Daytona has as ordinary a bracelet as is made; the Overseas bracelet in exceptional for stability, comfort, and design. Some people prefer one over the other.
The Daytona feels lighter and more flimsy than the Overseas. Some people prefer one over the other.
The Daytona has a tach. scale that some people care about.
My own view is that a steel Daytona is just an ordinary Rolex of no interest, while a steel Overseas Chrono. is a thing of beauty and a great companion, but I recognize this is a choice based on taste and style, not necessarily superior performance. The white gold Daytona with silver dial on the other hand is something special for which VC doesn't yet have a comparable offering. I still have my fingers crossed that VC will someday make a white gold Overseas on a bracelet with a blue guilloche dial.