I am in the process of quilting a "generous" sized queen quilt right now on my Janome 6500. The batting I'm using is thin. I think the name of the batting is Thermore. It has NOT been a problem at all. Right now I'm just doing stitch in the ditch but I don't see that there would be any problem if I was doing FMQ instead. I've done SID quilting with my other older machine which has about a 6" throat & I did a queen log cabin on it. That was a little harder to turn the quilt but still doable. Have also FMQ several generous full sized quilts on the older machine & it went just fine.