Sweet looking bike! Do you have any pictures from behind? I am thinking about getting those cans, but I have the R&G tail tidy fitted and am a bit unsure if the indicators will fit with the hexacones. Thanks.
The quality of the sound is a subjective thing Fennell, all you can say is you like the sound of the twin hi pipes better.
I have CF Arrow half system on my 06 speedy (twin pipes) and recently I, and a mate had our bikes tuned on a dyno by Wayne MacDonald (Tuneboy) in Sydney. He got a really good result with mine (about a 9hp gain). My mate has an old 05 thats done over 100,000km, and he has a very short, homemade cut down dirt bike pipe on his bike that is not much longer than a CW. His bike produced more power and torque through the whole rev range (except for the last 200 revs before redline where mine slipped past with about 0.2bhp more.) So I don't think you can make a claim that twin high pipes produce more power and torque in the low to mid range. That was where the old 05 was strongest.