Some panels degrade the contrast/gamma/colors at higher refresh rates while lower (60hz) was usually on target.
The VG248QE was really good at doing that. There were actually different ICC profiles for 60, 100, 120 and 144hz refresh rates I think on tftcentral or pcmonitors.info review of this, since the quality changed so much. The gamma literally went from like 2.3 to 2.17 or something (actually I think it went down to 1.8 just from refresh rate increasing)
My XL2470Z looks almost exactly the same at 60hz vs at 144hz. No different calibration or OSD settings needed at all.