I'm currently running 35x12.5-15 MT/R's and I love them. Great traction and nice ride on the street.
They are definitely louder than an A/T tire, but a lot quieter than any swamper or aggressive M/T tire.
I hope I get anywhere near 35k miles out of them. They are really expensive to replace.
Even more expensive if you are running a 16" or 17" rim.