I have a Hinterberg frame, and I love it. I start quilting at one end and then go to the other. It's a 3 pole frame so I don't have to baste the quilt, and it tilts so it's comfortable for me to work with. They no longer make the model I have, but I think the newer Hinterbergs are similar. The company has been very supportive, too.
However, if I remember correctly, the Grace is also a 3 pole frame, and I think the Grace Company is supportive, too. So I can't really say if one is better than the other.
Janet