In June/July I completed a 3,000 mile trip from Denmark, across Scandinavia, down through the Balkans and back through Germany on a zx10r with a us20 and an r25.
I'm not saying it was comfortable but I got to where I was going bloody quick!
Unless you're camping there is no need for masses of luggage and as for a GS1200 and the like, forget it. Too big, too heavy.
Sounds like you had a great time. Nice one.