As you are finding out - this question has many answers. Each board member has their favorites.
To answer your question directly - all those that you mentioned are good machines and each brand has machines that range from OK to fantastic.
I have sold Vikings and owned Vikings, Babylock and Pfaff. My personal favorite is my Pfaff for piecing because of the IDT. But the others worked fine for sewing and quilt piecing (just had to be a bit more careful). One lacked multiple needle position the other was excellent but lacked the dual feed that the Pfaff has. If you are in an urban area - and have a big sewing center - go and play on every machine possible.
I have two Pfaffs now - both bought used (one off Craigslist). Your ultimate decision will be based on features, availability and price - good luck.