My monster ovals on on the 2nd bike and have over 100K on them.
Chrome still looks great, except on the bottom where they are all scarred up from dragging the pavement

I believe that they have gotten a bit louder and even deeper than when new. I, personally, think they sound great on the 110. I pulled into the parking lot at the dealer to meet some friends for a ride last week. Another CVO owner told me he knew it was me without even looking.
Only issue (other than that they weigh too much) is a rattle in one of the pipes with when cold - like below 40F. This goes away after they warm up a bit. I mentioned it to the V&H guys at Daytona last year. They said that they could guess what it was, but should not ever be a concern.
I'm considering moving to the Monster Rounds for better ground clearance. Hey Master Guns, how do they sound compared to the Ovals?