27' Imac-swap out screen or complete replacement of computer?

[ejosepha]

I have the 27'" Imac with slight yellow tint on bottom and grey bar shadow running along the bottom as well. Additionally, the buzzing sound when brightness lowered below 50%. The computer works great otherwise and I don't hear buzzing when at normal distance from screen. My dilemma: Apple has offered to send a technician to my home to replace the screen, and they said that whould also fix the buzzing noise at lower brightness at the same time.
My question is have people been satisified or had better luck with screen replacements rather than simply asking for a new computer in exchange. If I'm simply swapping displays to get the same results, or even exchanging computer to only get the same results or worse, I would rather delay this interaction until a real fix is in place. My current Imac has no dead pixels, and works great except for these issues. HD makes a grumbling noise, but I think WD Black Caviars are known to be a bit noisy.
Any advice on way to go would be appreciated. Swap out display? Exchange computer? Stand pat?

[Matthew Yohe]

They aren't offering a new computer though, they are offering to replace the LCD.

You want to delay this until...? I don't get it.

[ejosepha]

I can either give apple the chance to replace the display (in this case they would send someone to my home to do it) or just ask for an exchange for a new machione, It's not clear to me through reading a few forums that either replacing the display with supposedly new screens without the issues, or just returning the Imac and receiving a new computer, that the problem will be solved. I'd like to hear firsthand experiences with either method to see which path to take. You'd think that in sending someone to your home to replace the display they must feel confident that they could fix the issue. But who knows. I'm reading horror stories with both options.