Medium format gear, when you start accumulating and wanting to take it all with you, will get really heavy really quick. I've shot Sqs for a long time and I've gone back to using a backpack for transport if I have to take everything out of its hard case. I work on location a lot and work out of a vehicle that can carry all my lights, cameras, and supplies so the Bronicas stay in a hard case or backpack most of the time. I second the F2 recommendation - They are great bags that have a lot of room for larger and heavier systems such as the SQ.
All the best-
All the best-