Quoted from Blake:

From my experience the short answer is no. I have seen EM's from the 60's and 70's that once thoroughly gone threw were more reliable then their WPC or even Whitestar counterparts.

I have seen NIB games that had issues before their first ball plunge.

And of coarse I have seen your average routed pin (all era's) that was a disaster and needed everything under the sun worked on before being made reliable.

After making said pin reliable I think you can say that certain systems (Most EM's, Early SS Stern, Williams system 11, Gottlieb System 3, Whitestar, SAM) were more rugged and or had less design flaws then others but thats usually only after addressing the known issues with that system.

To me, certain problems like (loose connections, switch errors, alignment issues, blown lights, weak flippers,exc.) are universal to pinball and I don't think of them as reliability issues. Just regular maintenance.

Thanks
Blake