The most and least reliable vintage movements?

[Micky]

Dear Prim specialists,

 

I would like to ask you for your opinions on the most reliable and the least reliable movements used

 

in pre-revolution Prim ? Would you say that cal 68 the most? ....and the least..... I have no idea

 

.....and you?

 

Thank you in advance.

 

Enjoy the sun

 

Best wishes

 

Micky