Robustness of vintage Rolex watches

[djdm]

After owning multiple new Rolex models I'm now considering getting a vintage Sub from the late 70s. As expected, my new Rolexes run perfectly, keep excellent time, and haven't needed servicing (all are under 10 years old). However, I am wondering how robust vintage models are, specifically late 70s Subs.

A few years ago I bought a vintage Omega for my wife and it has been nothing but trouble, even after a complete servicing. The main problem seems to be that the watch is easily magnetized and loses/gains time regularly.

What should I expect of a recently serviced late 70s Sub? Will it be "delicate/unreliable" like my wife's Omega, or robust like my new Rolexes?

Thanks in advance for your responses!

[Xantiagib]

I Cycle to work every day wearing my 1970 1680 @ 12kms round trip - and the roads aren't too good either -

Once the hands fell off a seiko I had pulling some luggage over a rippled surface

[Old Expat Beast]

https://www.rolexforums.com/showthread.php?t=560827