My .02
So, the store is opening up a number of boxes, then firing up the machines until they find a few without this issue? LOL!
That sounds a little extreme doesn't it? On the other hand, I don't expect Apple Stores are going to put yellow screen iMacs on display either.
I've been perusing these yellow screen threads in the forum. Some posters say this issue is very rare. But when something like this happens to a customer then the fail rate for them is 100%. One guy started a thread as he's on his 3rd 21.5 iMac for yellowing.
Imagine you're a long time Windows user who has decided to take the Mac plunge. You even go all in for the 27" 8GB RAM, 2TB drive, and so on. You pull it out of the box, fire it up, and WTH!...
Another poster said buy a second monitor. Such workarounds aren't acceptable. Apples are premium PCs, you're paying extra for the OS, the design, and the hardware. I haven't seen an add where Apple said "Well, we are using Intel and Seagate components now, so some substandard parts are going to get through." I think forums like MR should hold Apple's feet to the fire, tell Apple that noisy drives and gray bars might be OK for Dell, but we expect more from you guys.
When I purchased my 20" C2D iMac I had some issues at the start. I ran the initial setup, it was OK a few days and crashed. I did format & reinstall, it was OK again for a couple days then crashed again. At this point I was starting to think Macs were a little overrated, my initial experience waasn't going very well. I called AppleCare, they had me format & reinstall, same result (personally I think it was crashing trying to download and/or install updates from Apple). Took it to the Store, the Genius hooked up some diagnostic stuff, booted with his CD, did some things I didn't understand, told me to go home and do one more format and reinstall. Went home, formatted reinstalled. That little iMac has run without a hitch since; screen colors look great, runs cool, and is quiet as a church mouse. I plan to have it for a while.
I went to local Best Buy to look at the current Mac lineup after seeing these threads on MR. First chance to see one right up close. My very first impression of the 27" was I want one. It really looks nice, and the screen was sweet! No yellow (even with changes in bright setting), no gray bars, relflections didn't bother me. Store was too loud to hear any HD noises but couldn't hear anything obvious. Other thing that hit me was the heat, this thing was really, really hot! I don't claim any IT brilliance but I do know heat is not a computer's friend, I have to wonder what long term effect that heat will have on the iMac?