I have a cheapy Ryobi Rattle Gun (Impact Driver) bought on a special rated at 120 NM. That's about 88 Ft-lbs. I have changed from using a torque wrench for the crank and clutch centre nut to the Ryobi, as I had calculated the force on the clutch was eye-watering, enough to damage the clutch main shaft. At this low torque, I am comfortable that I am getting greater than the recommended 65 ft-lbs. I watch it rattle until visible nut movement ceases - then a few rattles more. I am a bit of a wuss when it comes to overtightening nuts, imagination always runs away to stripped threads. I also don't use the soft BSA lock washers, just Loctite. Nothing has come loose yet. I don't use the rattle gun for anything else on the bike.
Col