‘Free seating’ is something I have never experienced on a flight before but at check-in that is exactly what I am told – and my boarding pass is essentially ‘seatless’.
My flight from Bagan to Mandalay sees me flying on Air KBZ in an ATR 72-599/600 series propeller aircraft! 
As I enter the aircraft through a built in door-cum-staircase at the back of the aircraft, I am offered a wet towel by the flight attendant and a warm smile. I try to sit as close to the back as possible but am requested to move to the front, so take seat 11A, a window seat, in a 2-2 configuration.
Throughout the quick 30 min flight there is naturally no food nor entertainment but candy is offered and there is a reasonably interesting inflight magazine.
One other point of interest: take-off and landing are incredibly quick / such a difference from the taxiing that jet airplanes need to do. Within 5 mins of entering the aircraft we are in the air and visa-versa on landing. 
Rating: 8.5/10