I have the 98Q. I've quilted queen size with no problem. I don't use a frame. I love this machine- workhorse is the perfect word for it.
Can't say enough good things about it. Just remember- it likes to be cleaned and oiled the every 8 hours, just as the manual says. But you'll be a pro in no time at all.
(I keep a small piece of batting on the side to wipe off the machine after oiling just in case I get sloppy.)
I am soooo glad I invested in this machine!