I have the 08 also, purchased in May. I see you still have the stock pipes - me too. I plan on keeping them - I love the bike as is. I did have to spring for the new seat and sissy bar setup for my girlfriend. The new seats came with a plug for a rider back rest, so I bit on that. I didn't really find a comfortable adjustment for the rider backrest on a 2200 mile trip. The best position was a way laid-back position, with just a throttle hand on the bars. Was kind of disappointed with the lack of vertical adjustment and the set screw lateral adjustment...not really Yamaha quality.
So screw the back rest. The rest of the Raider is fantastic...so much power and great cornering on the mountain roads. I am blown away by the Raider. 'Hope you like yours!