Vacheron Constantin was founded in 1755 -- 20 years before Breguet. The oldest continuously operating watchmaker.

Breguet invented the tourbillon, automatic winding, and the hairspring. More historical innovation.

Breguet's guilloche dials and coin-edge cases are more distinctive. Instantly recognizable.

Vacheron Constantin holds value better. Overseas and Patrimony are more sought-after.

Both are at the pinnacle of finishing. Geneva Seal quality from both manufacturers.

Breguet starts slightly lower. Entry-level pieces are more accessible than Vacheron.