if you use enough gear muscle loss is not an issue in any diet but dnp speeds things up and even without gear muscle loss is less because your catabolic diet period will be over more quicky.
it might be overrated but not any more dangerous than driving a car, if you steer in the wrong direction you will end up dead but most people drive for decades without an accident. why is it so hard to count with one hand? take 2 capsules a day and you will be fine, take 5 and you will probably die.
overrated ... lets say your metabolism increases by 30%, you might have a bmr of 2000 cals/day, so it burns an extra 600/d, makes 2 lbs of fat per week on top of what you would have lost w/o dnp. a 2 week cycle with a calorie deficit and some workouts can shed 6 or more lbs of pure fat off your body, i call that impressive. of course, you can achieve the same amount of fat loss in a month w/o dnp.
the real use of dnp is in very thin women who have driven down their bmr due to extreme dieting and for contest prep.