My 1st quilt machine was the Viking Mega Quilter 9" but on a Grace Frame as I wasn't impressed with a metal Inspira frame at the time. Loved the machine, never had issues with the tension but the throat space made it hard to quilt those larger blocks. Added a PCQuilter robotics system to it and their MaxThroat to give me more throat space but never could get the MaxThroat to work correctly. PCQuilter has issues too but that may have just been my system as others find it works great for them. Moved up to another machine with an 18 inch throat but now I wish I had kept the MegaQuilter for regular sewing as I'm now looking for another simple machine to sit on the cutting table to add the binding onto the quilts as it would give me more room to work on.
Again, the MegaQuilter was great for me and of course I have their Designer 1 (combo embroidery) machine I do all my piecing with these days.
I feel you got a great deal if the machine and frame are in great working condition.