My friend has the Hinterberg frame for a mid arm and likes it. It was the only one she could fit into her room, hence her choice. I have a longarm and would advise you to buy the most sturdy frame you can, because vibration isn't fun while you're quilting. You also must be able to level the entire thing so the machine doesn't drift and so your patterns don't get skewed. Mine is a Gammill, with very heavy steel, well made and stable.