I ride like a complete panzy, I will admit it. I use mine mostly for commuting to work and back, and I like to keep the RPM's pretty low (3700). I keep pretty good records of miles driven and gallons used.
I think a common mistake is that people will give average mpg for one fill up, which is wildly inaccurate. Over the past 1000 miles or so, I have gotten a low of 49 mpg, and a high of 59.6mpg. The last two have been between 56-59.
In reality, it is a little lower than that, since the odometer is a little generous (from what I hear).
Either way, I am happy with the mpg, plus if I am out riding for fun it has more power than I need. Can't ask for much more than that.