past Pateks (perpetuals).
Both are quite attractive and yet each has an entirely different visual appearance.
I suspect those who prefer the case design and dial layout of the 3940 will be more attracted to the 5146 while the 5396 offers the feel of the 3450.
I like both and would have a hard time choosing between the two but, without studying the watches and relying on first glance, would probably gravitate to the 5146.