the start right frame has 2 problems that i hear over and over again
1 - the teeth on the ends of the rails break often when rolling the quilt.
2 - the welding on the joints is so heavy that when you roll over those areas with the machine carriage you could skip stitches.
you might want to join the grace frame yahoo group - they have a database of items for sale by users.
plus you can search previous posts as ask the group how they feel about their frame.
i think most feel they got exactly what they paid for and are fine with that.
i would adhere to the throat size and weight limitations that the grace frame states to avoid issues with further breakage of parts.