And I disagree that the F 650s are underpowered. The current 71 hp is enough to cruise at over 100 mph with full saddlebags. When I had my F 650 Funduro, with its 50 hp, I would ride all day at 70-80 mph with full saddlebags, duffel bag on the back, and a tankbag on top. More power can be fun, of course, but you don't really NEED all that much.
I also disagree that the F650GS is underpowered. I just returned from a 10-day Alaskan tour where I rode a rented F650GS (Single) 2-up with my wife Jane. While the bike was a bit cramped from a size point of view I had no trouble keeping up with my Harley V-twin riding companions. Now I am not particularly interested in 100 MPH riding, but I could easily keep up with 65-70 mph on the road. The only difficulty is that I am used to a R1200RT with its nice windshield and found a 65 mph wind load on my chest a bit of a challenge (and a definite cooling feeling). But the bike was great on the Alaskan road especially in the ubiquitous construction areas. Since I was riding with a Harley guy that was a fanatic about his bike and its appearance, we were strictly on paved roads (except for the construction areas), but when we were in these areas I found the bike great to ride. Note that this particular bike had been lowered to about 28.5" seat height -- important for me since I am dimensionally challenged in leg length.