The main benefit and why we upgraded is the GL has a kitchenett in the studio side so we can lock off the unit and only use the studio if it is just two of us going so for us it essentially doubled the time we would use it, the GB has no kitchenett in the studio, no dishes, no micro, no sink.. Plus the size.
Plus all the other benefits you mentioned but doubling our time by locking off was the main one for us.
