I have 2 OLED Sirloin, one of which is the Alienware 34", the other their 32". The 32" is 4k, the 34" is 2k.
One very important thing to take note of regarding the 34" Alienwares - they make 2, one is Freesync 165hz, the other is Gsync 175hz. The typically less expensive Freesync version has a "glossy" screen, and looks far superior to the non glossy Gsync IMO. Which is why I went with the Freesync version instead, despite wanting Gsync instead of Freesync. They frequently go on sale, mine was $999 CAD from the Dell store in Canada.
I had the previous 34" Alienware non OLED monitor, it was excellent and served a long time, and also ran the LG 27" 4k 144hz Gsync with that as a secondary. I much, much prefer the OLED 34/32" setup I have right now.
No burn in issues so far either. Pixel refresh - just be sure to let it do it while in standby mode. Typically after 4 or 5 hours it'll need a refresh and it takes 5 minutes or so. You can also do a full panel refresh that takes on hour or so, and every 20 hours use they recommend doing that. You can set it up in the monitor controls so it doesn't surprise you with an automatic refresh and interrupt what you're doing, just make certain you do the refreshes manually when you're done using the PC and you should be fine.