I have a Bernina 590, and absolutely LOVE it! I also work at a Bernina dealer. The problem I see with the newer machines is that you absolutely have to hold the top thread tail when you start. That's not a problem for me because I've been in that habit since Jr. High. If you can do that, it will take care of a lot of problems. Like thread getting caught in the hook toggles or thread cutter.
What specific problems are you having with your machine?