I need to learn about cordless impact wrenches before making a purchase so I have some questions. Do they hammer same as air? Can you set them for different torque settings? What torque is good for anything around the house including my truck, lugs, etc What is the difference between the 18v and 20v? They both provide similar torque ratings. Are there any more? What is the trending/newest/longest lasting/best battery type? I read descriptions like Hog ring, anvil ring, friction ring, and detent pin. What are the benefits of each, which is desirable? Experienced cordless impact users, how reliable are they compared to air? Does the battery slowly degrade like lithium? Anything else to consider Thanks everyone.