What are you referring to when talking about resting? In theory, if your temp inside the "rest box" (oven, cooler, etc.) is anything less than the current temp of the meat, then you're technically no longer cooking it and are just slowing down the "cooling off" process. How much you're slowing down the cooling off depends on the difference between the temp of the box and the current temp of the meat; a box at 170 (oven) is going to cool a lot slower than one that is at 100 (or whatever a cooler is when you throw in a butt that is wrapped in towels). And since heat loss is faster with conduction than evaporation, a butt in a cooler and wrapped in towels is going to cool faster than one in foil (it's the same reason food thaws faster in 35F water than it does on a counter at 70F room temperature).
If you're talking about butts, brisket, then an oven at 170 will cause a very ling rest period. If you're talking about prime rib or steaks or a tenderloin, then a rest in an oven at 170F will still be cooking it.
Sorry for my very left-brain, analytical response. I just can't save me from myself sometimes...