While accelerating it's louder because you hear the turbo noise. At idle, the only noticeable difference is that you do smell the diesel exhaust but I don't think it's bad. My wife has a very sensitive nose and she doesn't like the smell.
The tune I have in the truck doesn't put off large amounts of black smoke or anything like that. The tuner can be set higher in which case it would be louder and put off more smoke. I've got mine now tuned to 120 extra HP and it can be tuned up to 200 HP.
I may have to put the truck back to stock if I decide to go with a MH. If I do, I'll be selling the "Cold air intake", EFE 4 inch stainless steal exhaust and the tuner. One dealer has already said he wanted my truck as it sits but I'm not sure what he's willing to pay so I might be better going back to stock to open up the field of buyers.
SOB "The RV Wiseguy"