Hey there,
I'm not sure if anyone picked up on it, but Mac video settings are by default brighter than that of PCs. If anyone is fortunate enough to have a PC and a Mac side by side, with the same build of Photoshop viewing the exact same photo on the same brand/model of display (same display settings) you'll notice this.
Also, a brand new LCD display may appear more brilliant than a well used CRT display.
I hope this helps.
Regard,
cHUCk in Melbourne :idea: 8)