Came across these head pipes and liked the fact that they are differnt. Anyone use them and have any comments? They are the ones where the front pipe runs behind the rear cylinder and out the left side. I have a 2011, the description says I just have to purchase the o2 adapter. Question 2, I pulled the baffles from slipons because the stock head pipes have the cats, and they were so quiet! Problem is I just moved and the baffles got tossed by accident. How obnoxious will my bike be if I go to a true dual head pipe and lose the cats with my open slipons?