Iceblossom, I think I have heard so often the 820 is so finicky that lots of folks did trade her in. I had the 570 that kept jamming and now have the 590 which so far has been wonderful. We don't have many choices up here for nearby techs so I pretty much have to pick between Bernina and Viking. The Viking tech is very experienced but the newer Vikings from what I hear are not like the old workhorse Viking D1 that I used to have so I have decided to stay with the Berninas. Also a factor is all the money I have in the accessories, feet, embroidery hoops, etc.
Zyngawf, I haven't had many issues with the thread cutters in either my Bernina or Vikings, but I have to say, I seldom use them. Just a habit I never got into except when embroidering and then the machines just default to cutting. I know that you need to clean the area around the thread cutter frequently and also be very gentle when removing the lint and threads around it. My 590 has a built-in video on have to do that but there are also many online videos. Bernina Jeff has a good one.