The Soft Italia 42L top case detaches easily and has a handle. Take that, other top cases! You can pack it at home, pop it on the mounting plate, and pop it right back off at your destination. There are no anchor screws to fiddle with, or adjustable straps to unclip- you just turn the key in the opposite direction and pull.
Don’t want it to be detachable? Fine, be that way. There is a lock on the inside of the top case that will override the latching mechanism.