It's all about what you personally like to do. I like the technical challenges, so I will spend a lot of time to make something work, repair a board, mend an old, old coupler, fix my shoes, etc. That is where I get the most pleasure right now. I really enjoy learning and doing....
My theory is when I get so so doggone smart I know everything there is to know about model/toy trains (not predicting any time soon), I will quit fixing them and just run them!
And just to get back on topic, if the OP is running PW engines with electronic couplers, I would agree with others that conversion might be possible and would likely require a bit of effort. But frankly, when I see how magnetic (button) couplers get all hung up on diesel frames and front ends, and open themselves if they are running on uneven track (dips and rises), I totally prefer the older electronic version - they look and operate better IMHO.