i have got 5 of rinnai hybrid heaters bought form al fatah, little pricey but they keep the atmosphere really nice and gas consumption law, you set the temperature and it regulates the room on it would even shutoff and re start when reached that temp, it also has remote control so you can control it form far away
cons is i don't know about other people but all of ours don't work on low gas pressure, they shutoff or show error, a normal heater would still be working at that time, they were useless when gas pressure gets really low, also they require both electricity (to power functions and blower) and gas to work, they also have a filter on the back which requires cleaning after a few days like AC filter
but in gas heaters nothing beats them , the room atmosphere and ease of convenience and costs savings in gas are great, plus remote control is a bonus!