Kuska, sorry I was not flaming you... I was actually responding to ChrisA's 99.9% of mac folks only are amature photographers comment. BTW, furthermore his dig at wedding video folks being hacks is a joke. Have you seen what these folks charge these days for their services? It is now a BIG high-end business, offering video, DVDs, websites, Podcasts, blogs, slideshows.... Jobs billing out in the 10's of thousands of dollars each (not bad for those AV-geeks that some may have chuckled at in their school days, lol).
Back to your point, which seems genuine. My screen indeed is very consistant edge to edge, top to bottom. There is some darkening on the bottom 1/8", but this is not really usable real estate, IMO. However, I am on the White 24", and not the aluminum new flavor... so take my experience with a grain of salt. Some monitors just calibrate with ease, and other brands/models just never get quite right. My old g4 had a 17" Studio display that was easily the finest and most consistant screen I ever had (until it died after 5 years of trusty service). It was accurate until the day it died, and then it was just blackness. I replaced it with a new Samsung 20" SynchMaster, with has a nifty TV tuner that does PIP, with little screens that can be moved around (and also full-screen HD quality). Nice and fun to work while watching the news etc... BUT that screen can not be be fully reliably calibrated (at least in my experience). Admittedly that is still plodding along on os9, and the software running my Spyder is OLD. My 24" is seemingly as accurate as my old Studio display, at least so far. My experience is producing files that RIP to plate-setters for CMYK offset printers (magazines, etc.), and it matches exactly my proofs. With the white 24's the complaint was that they were too bright. I tried a third party app to bring the brightness down (it was a train wreck, lol). I simply adjust the brightness to it's dimmest setting, and then ran the calibration on my Spyder. And Bingo!
Calibrating output to one's own printer is WAY more difficult. After 5 years of tweaking frustration I am happy with the output from my Epson 2200, and my newer Canon Pixma. That process NEVER seems to go as smoothly, and perhaps is better suited to someone with a longer attention span than my own, lol.
Boy I am wandering here, lol. Back to you...your screen being uneven is a cause for concern though, and unacceptable if it is a screen defect. I don't know if this is could be a video-card issue, or a backlighting issue, OR a true screen defect. In the "old-days" left to right uneveness was caused by electro-magnetic interference (phones, magnetic devices, etc.). I do not know if LCD screens suffer the same effect (have you tried moving your computer around, or to a different location as a test?). If you are unlucky enough to keep picking the one's that do have issues, just keep taking them back until you get one that works properly. Since you are experiencing "issues" buy an AppleCare plan and extend the coverage to 3 years, if you haven't done so. I usually DON'T do extended warranty plans, but for laptops AND iMacs I make and exception. I recently added AppleCare for my own iMac. But again, in case you missed it amidst my rambling, lol... my white 24" is consistant side to side, and edge to edge (barring minor darkening on the lower 1/8"). This is when viewed againest Pshops fullscreen, neutral background mode. cheers, michael...