I have the 3/8, what information are you looking for?
The biggest concern to me is exhaust location, it's in the head of the impact. If you're not paying attention while wiggling it somewhere, the exhaust outlet can be pointed directly at your face or into your ear. You don't notice this, and blast your hearing. Same with the rotating handle, you need to be aware of how you're getting it into a space, as you can pin the trigger down. It's a nice tool to have, but you need to think about how you're using it.