I purchased the Bernina 440QE a few months back and I absolutely love it. It has a self-threader which was initially a little difficult to use, but after a few times, it became no problem at all. I've used some of the fancy stitches that are standard to make labels (alphabet characters) and other doo-dads on various projects. They all work just as they should.
The Bernina should come standard with a plastic extension table that slides on and off. I have found it to be adequate to my needs. I'm aware that there is a larger extension table that is optional, but I have not felt that I needed it.
I am very, very happy with my machine. I think it has made me a better quilter. I didn't really want a new sewing machine when I bought it, but I was so frustrated with my basic Janome machine that I just decided to bite the bullet and do it. I have never looked back. My new machine was easy to learn, and we are happily sewing like old friends. I don't know anything about the Viking, so can't comment on that.