You probably got the Developer Edition HTC One so you could tinker with it or update it without carrier interference. Your hard-earned money is now rewarding you with HTC’s Android 4.3 update. HTC has made available a full-fledged flashable ROM.
Just download and flash the ROM, and you’ll be ahead of the game. Especially since in the US where most One’s are still running 4.1 (all carriers minus Verizon, which has 4.2). Of course, older ROMS are still available should you want to downgrade, but why would you want to?