People have been using their 2017 OLEDs with no "permanent" burn in at all and these are people that say they have racked up hours in BF 1 amongst other games with heavy HUDs. So far I've had 4+ hour sessions on mine, not a sign of anything at all and if anything does appear, it will go with a compensation cycle that runs after every 4 hours of usage whilst in standby and for any severe burn in, there is a more thorough compensation cycle run. Of course if you are using it for desktop usage 24/7 then yup there might be some "permanent" burn in eventually but most people aren't that stupid....
2017 OLEDs are 120HZ @ 1080P
Yup no sync is a bummer, maybe next year TVs will have it but not an issue for me especially with amds new sync, it is extremely impressive and there have been a few people who have been happy to give up sync just to have all of oleds superior benefits.