I have an '07 and use the stock handlebars and seat. I have done lots of 7-9 hundred mile days, and rode straight home from Tennessee a couple years ago. 1410 miles in one shot.
When I transitioned from my VTX to my FJR, I was a little sore the first few times, but like most things, I adjusted quickly and gained new muscle memory.
LOTS of people on this board are way too sensitive to let their body adjust to anything, so they freak out when their first ride feels even slightly different from what they rode before...If they even rode.
Then we have the group that will find anything there is to complain about and complain. If I had never come to this site, I would think I have the perfect bike; however, after hanging out a few years, I have realized the problems lurking.
Let's see: The seat sucks, the windshield sucks, the bars suck, the kickstand sucks, the headlights suck, the shocks suck, the vibes suck, the alternator sucks, the battery placement sucks, the clutch sucks, the 5 speed transmission sucks, the low power output sucks, the mirrors suck, the brakes suck, the heat sucks, the weight sucks, the horns suck, the blinkers suck, the ignition switch sucks, the electrical system sucks, the cam chain tensioner sucks, and if you listen to a rogue contingency that plagues this board, the motorcycle tire on the rear sucks.
Did I forget anything? Ride your bike the way you want it, and don't fall for the "Oh, now I need one of these" crowd.