I have a Pfaff Creative 4.0. It has a built in walking foot and a 10.5 inch throat. I have quilted several smaller quilts and it works wonderfully. I am sure I could quilt larger ones too, but I just haven't. There is an embroidery unit that goes with it, I just don't have the time to do the embroidery so I didn't spend the money to get it.
I have had Pfaff machines for 30 years and I wouldn't own anything else. I am sure most ladies feel the same way about their machines. It takes quite a bit of research to find one that fits you. But the research is well worth the time if you find a machine that you love.