Personally, I do think Patek Philippe ruined their flawless perpetual calendar after the reference 3940 (as shown in the photos above). What drew me into vintage Patek was their subtle elegance that you feel when wearing it. It's just so great and well-proportioned, which is something I hardly find in modern Pateks.
I used to own a smaller, rather more "vintage" Ref. 96 with Breguet numerals, but there are certain points you might want to consider before getting into vintage pieces.
Serviceability and the cost of servicing. That's only if you can find someone with the skills and know-how to service your timepiece without messing it up. As far as I know, Patek will not reshape the case unless absolutely necessary. I sold my Patek reference 96 mainly because of the uneven case shape - it's just the little frivolous details that a watch enthusiast like me would notice, even if others wouldn't care too much.
Resale value. Not everything has the upside appreciation once you fall out of love with it. Then you realize there is no market for it. That's why people suggest buying a Rolex as your first watch, just in case you might want to sell it later on.
Fragility. Wearing a vintage watch doesn't give you the same peace of mind. You might want to wear it with extra care and avoid getting it near water.
Don't get me wrong, I love vintage watches, but these are a few points to think about before getting one. It's your call, your watch, and your wrist. After all, no one buys an expensive timepiece just to tell the time anyway. DD.