I have 2 rolling cases. When I bought my Janome MC6600P from a LQS I bought the recommended rolling case -a large Tutto case. Figured they would not sell them if they were not good for the machines. And my other one is one I got at Joann's. It was on clearance AND they let me use a 50% off coupon, so it cost about $20.00. And it has been going strong for over 5 years ago. I use it for my FW and my small traveling machine.
Neither is built to go tumbling down a flight of stairs but there are straps in them to secure the machines from moving about. And you can pad them with cushions if you want to protect your machine more, but I don't.