I just tried the HQ Swaat 16 sit down and it has ample of opening for a King size quilt to be done. I am looking for a machine on a frame but since I was there I just tried it and I really like it. The throad opening is both wide and very tall. At home I have done my quilts on a Janome 6500 (slightly larger throad opening). I wished I had had the HQ Sweet 16. Definitely use machinger gloves to hold onto your quilt. I also agree the best is to try it out.