The problem is - at least for me.... I can't count on using the full 1.6 gallons on the current bike like I could on the Gen 1. The current bike will only pull about 1.3. What good is the fuel capacity if you can't burn it? I used to count on 60 miles for reserve count up - 40 mpg (which is VERY conservative), 1.5 gallons. Now, I count on 50 and I'm looking and planning to stop at 30.
It's not a big deal East of 110 longitude. But west of there - it can be. I like to tour in the remote mountainous places. I've had a couple of situations where I've had to re-direct my route 20-30 miles so I'd be sure to cross a town that I knew had fuel, or risk running out in the wilderness.
6.4 gallons is still a big tank - I just think Yamaha should be realistic.