I really prefer my bikes to be quiet as possible. I don't know why, but, I just do.
My Super Bronc with the spark arrestor muffler, and a down pipe putting it straight down under the bike is super quiet, the hill topper with its factory muffler is quiet too, you can barely hear it go by.
As long as you take care of the motor it will be super reliable. I'd be more worried about other things, clutches, chains, ect.
This weekend, I filled the super bronc up 3 times in one day out cruising with it, no trouble at all. I do carry a cresent wrench in my pocket.....last time it broke down was my stupid fault, but I could of fixed it in less than 2 minutes with a single wrench.