Pretty sure the metal ones don't interfere with the computer considering my Bernina CAME with the metal ones. I think it's just important to use the correct ones on your machine as it could ruin the bobbin area if an incorrect one was used.
I second the suggestion to use a 60 wt thread for your bobbin. When I switched to Bottom Line thread for my bobbin, I was amazed at how long I could sew without needing to refill my bobbin. It just kept going, and going, and going..... :)