MetaMind I owned a Royole Moon for a few days before returning it.
The Moon's 1080p OLED displays' colors weren't as good/accurate as Cinera's. The Moon's contrast was better than Cinera's, but the black level was surprisingly disappointing for an OLED display. Also, the Moon's darker tones were muddy and brown-tinted, which I didn't like.
The FOV experience for me was about the same as Cinera's, although the Moon's design allowed me to get my eyes much closer to the lenses.
The input lag on the Moon was noticeable compared to my low-latency gaming monitor, but it was worlds better than the unusable input lag that Cinera has. Also, the Moon didn't have the tiny sync discrepancy between the two displays like Cinera has.
Ergonomically, the biggest issue I had was that the Moon's eyepieces would fog up constantly due to the way it presses against your face to seal out ambient light. The other reason that I returned the Moon was that it didn't support frame-packed 3D for blu-rays, only offering the half-resolution SBS format. These two things were deal-breakers for me and the main reasons why I was interested in Cinera.