Toby drilled his exhaust, mine is still stock. I like the way his purrs, deep, throaty rumble that I can hear behind me, which lets me know where his bike is in relation to mine. It isn't so loud as to call attention from the authorities, but you definitely hear his bike before mine. I haven't changed my exhaust at all, I prefer the stock sound level. I will likely go for a cobra slip on someday, but not to change the sound, it would be so I can use larger saddle bags.
I like the sound of the drilled exhaust, and it only cost the price of a larger longer drill bit.