One of the reasons that I love my JUKI TL-98P is that when they made the throat of the machine longer they made it taller too. Many of the other longer armed domestic machines on the market are only longer. Now long is good. I love having those 2 extra inches. In fact they seemed like miles more room when I first switched over. But once you put a sewing machine on a machine quilting frame the height of the arm really makes a difference.
It matters, as you can see in the photo because the first fabric bar is going under the arm of the machine. And as the quilting progresses the fabric rolls on to this bar and the roll gets bigger. That's where the height comes in handy. The JUKi TL98-P is 2 inches longer AND taller. The extra inches don't matter much when you're starting out. But they make a big difference as you come to the end.