Quoted from Pinkitten:
I bought my NIB WOZ in 2016, it was born in late 2015. It has the 1.1 boards, after they went from 5.0 to 7.5 volts I believe. But I don’t think mine are 2.0. They say 1.1 on them. I have about 700 plays on it, without any issues thus far. I am concerned that the 2.0 kit might become limited or difficult to get. It’s not cheap to buy the entire set of boards I imagine. I wish I had more clarity on how reliable the version 1.1, 7.5v boards are. I hear people have had issues, and others have had none. Difficult to gauge.
It’s a bit of a crap shoot, with some people reporting that they have had no or minimal issues and some reporting many issues. You have been lucky so far, but odds are you will have a problem with at least a board at some point. For some, when the problems start, they just seem to continue. The most reliable board set, and the one that will continue to be supported going forward is the 2.0. I would say it depends upon whether you want to keep your game for the long haul. If you do, upgrading makes sense. If you think you will just keep it for another year or so before selling, then you could risk it.