I have a Viking Quilt Designer and I love it. Before I bought the Viking, I had a Bernina QE (I forget the model number). Honestly I didn't like the way the stitches looked. The best way I could describe it it like this:
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They would be striaght, then go crooked. I brought it to 3 or 4 different dealers to try to straighten the stitches and nothing worked. I sold it and bought the Viking.
Be sure you test drive both. I also have to say the Bernina had a lot of thread bunching when starting to sew, the Viking not as much.
Just my experience with both machines - not saying which would be best for you. :D Good luck! :D