My friend in Arizona loves her Berninas and gave me her last one (which she replaced with another Bernina). She says her current one is less fussy but that the one that she gave me (the 820 "sewing computer") really prefers Aurifil thread and she often uses decorative and fancy threads. I'm finding that while I can use my remaining stock of Dual Duty, that it just purrs happily with the Aurifil.
I clean out the bobbin case area often (more than just when replacing the bobbin) and put a pair of long handled forceps by the machine to get those nasty little threads out of the bobbin area. With my vision issues though it can be quite a struggle, first to see the thread and then since I really have no depth perception to actually catch it.
Good luck!