The date/day mechanism on the 1555,1556 and 3055 isn't the best, they are fiddly and prone to failure.
I have litteraly spend days on fixing old DayDate mechanisms, changing out every damn part and still no instant date change or some other problem.
Now if they're in good condition and keep them that way and don't play with the day/date too much you'll be fine.
When they introduced the 3155 in 1989 they got the most solid working mechanism, if I were to get a DD it would be one with that movement, preferably a 18238 because of the brushed lugs, also still have the option for an onyx dial on that reference
If you do want vintage, just make sure everything is in very good condition and try advancing the time to see if the date change is instantaneously.
