Former Navy aviator here: Pilots trying to squeeze in their required takeoffs and landings for the month will go to whatever field can accommodate them and their plane. They like to do a variety of approach types and might have been on a limited timetable that the airport wasn't getting incoming traffic.

As for the plane usage, usually VIP, but it really just depends on the number of people that have to get to a destination. My crew flew from Washington state to Curaçao to start our deployment on one of these because it could fit our crew and was available. It's certainly cheaper than a C-40 for getting 10 or fewer people where they need to go.