The Breguet XX Transatlantique is more dressy and classic than the AP Millenary Chronograph. I sometimes wear my wife's Transatlantique and the only qualm I have about it is the crown is too small. Makes it very difficult to manually wind the watch when I have to (yes I know it's an automatic). Size is 39mm.
The new AP Millenary Chronograph comes in a 47x42mm case, so it's larger than your mentioned 40mm. Much more sporty and flashy when compared to the Transatlantique.
Both have solid casebacks.
Cheers,
Anthony


