It is great advice to test drive the exact model you are thinking of buying. I have a Bernina and absolutely love it. That being said, the Janome's are decent machines too. The new Janome Horizon is awesome! As far as the Bernina's go, consider a used one from a reputable dealer. They come with warranties and keep their value, so you can trade them in, just like cars.
Good Luck with what ever you choose and don't forget the pics.