My wife use to do king size quilts on a 5.5" harp size. NOT ANYMORE and it was ugly do that work. I think that the Soprano is the same machine as what we bought, which is a Brother NQ1300PRW. I will let you know that machine has a 8.25" throat - DON'T forget about the extra 1/4". From 5.5 to 8.25 was a world of difference. Check out prices on these two machines and don't get too caught up on which brand - they are the same to my knowledge.
I would be looking at whoever has the best service, offers some good training and has a good reputation in the area. I've seen these machines list for $1995 and sell much cheaper. Don't be a hurry and get a good deal. We paid $1250 and last year they had a $100 rebate on top of that.
Very happy with the Brother.