O-Rings - Yay or Nay? : MechanicalKeyboards - reddit
It depends. I hated O-rings until I got some really soft, thin ones. To my surprise, the cheap red ones on eBay were better than some expensive ones. Just try to find really thin ones! That said, I use them on some boards, but more often not. MX Blue, plate-mounted, thick POM keycaps: No O-rings. MX Blue, PCB-mounted, thin PBT: No O-rings