I think people are advising you to stay away from Singer/Viking/Pfaff because they are now made in the same factory and are not of the calibre as when they were made in Sweden (Viking) or Germany (Pfaff). Singer's influence has resulted in many changes for both brands and some of the newer models have been quirky. I think the Expression/Sapphires have been tweaked along the way so they now work much better. For dependability, Janome is very good and BabyLock also is excellent. At $600, you might be able to get a BabyLock w/ the automatic thread-cutter and the super-cool needle threader. Some of the newer machines now have the start-stop button which I have grown to appreciate more than I thought I would. Variable needle positions are important and the lock-stitch feature. Check which machine makes it easiest for you to achieve a perfect 1/4" seam as that what you will be doing most.