Dial side: With some common elements of style. The Patek has its two sub dials located under the 3 and 9 o clock line, while the Montblanc is well centered. Some will like, others won't.
Movements: Cal CH 29-525 for the Patek, Cal 16.29 for the Montblanc Villeret Minerva, which is almost 10 mm bigger than the Patek. But with a smaller power reserve ( Circa 55 hours for the Montblanc, 65 hours for the Patek ).
As for the finishings, the Montblanc wins, clearly.
While for the case, the Patek wins. Smaller, 41 mm instead of 44 mm, thinner, 11, 45 mm / 13, 5 mm, better finished...
It is interesting to compare them, I think.