Personally I love the Pfaff's due to the IDT [dual feed] technology.
Like others have said before: have your wish list with you and your price limit. Try them all and see which one you bond with the most. Most dealers will push how many stitches the machine has, but stick to what you want. No need for stitches you won't use.
I'd also consider a used machine. Many quilters/sewers will be trading up at the shows.
Bargain for all you are able to get.