Sort of
I stumbled across a blinding deal for a new Grand America which included free servicing for 3 years. My wife is an experienced pillion who's arse has graced all manner of bikes including GSA's and full dress Harleys. She reckons the GA is the easiest bike we've had to mount and one of the most comfortable to sit on. It really is effortless to ride and hides it's weight and bulk well. The Bagger and GA are basically the same bike with the addition of a top box which is not designed to be taken off. You cannot (easily) retrofit a top case to a bagger but you can remove one from a GA but it is a little involved and you will need to fit an auxiliary brake light as the brake lights on a GA are on the top case. Why remove the top case? Because when riding solo it acts like a giant wind dam and upsets the stability of the bike at speed which is why it's restricted to 103mph! If you want more detailed info let me know. Also K1600 forum has plenty of info on both bikes.
The small bag behind the back seat is fixed to the rack that holds the top box. The rack can be removed but opens up a can of worms with hiding the exposed electronics under the seat