The Sony RX100 V “just like the previous one except for the AF.” The RX100 V and RX100 IV are very similar except the RX100 V AF is a monster and it can record for twice as long at 960fps. Being an original RX100 owner I have never experience any heat issues with my Sony RX100, but apparently recent RX100s that do 4k can get very hot just like the a6300.