Our airline (Beech 1900s in the United States) does this on a daily basis. Shut down #1, swap pax and paperwork, and you're off an running. I find it handy on occasion, (if we're just dropping pax at an intermediate stop), but don't like to do it much. If people are borading, then they must be briefed in a very loud cabin, it's difficult to communicate the basics like carry on stowage with them, it generally adds to the chaos factor.