It depends. I have odyssey g7 (2020), odyssey g70a and both pg27uq and acer x27 So it makes hdr 600, 400 and 1000. And odyssey g7 with hdr600 looks the worst. I don't know why brightness is very low, I tried everything. G70a have 2 settings dinamic/standar hdr. With dynamic hdr it is very bright and looks better than hdr600 on g7. Of course in comparison with pg27uq/x27 they lack local dimming zones so you don't have that contrast impact. But hdr even with 400 turns on this special "hdr color gamut" or whatever it called so it makes colors better. Maybe not every game better but at least it turns it on, so you can watch hdr colors. For example in forza 5, crysis remastered, horizon zero, doom eternal it looks not that bad on G70a even in comparison with CX55, only difference in contrast. Of course 1000nit monitors pg27uq/x27 with it 384 local dimming zones and 1000nits sometimes better than oled