I have an Inspira frame on my Viking Mega Quilter 8x18. Have had it for 8 years now, and have not had a problem with the rollers bowing. My husband set up a dead arm on it so I don't have to roll the finished part of the quilt and that was handy. I have had a lot of problems with the machine, but the only issue I have with the frame is the black inserts on the carriage (where the machine rolls). They tend to wear off and need to be replaced more often than I like. When I got the machine it came on this frame. They gave me six extra pieces for the rails, and at this time I am down to two extra. The worst one is the one the encoder runs on. I like the frame, myself.