I'll try to man up, but I'm a girl!
So, here's a little update:
UPS arrived when I was opening my front door today, so I couldn't really ignore them and pretend not to be in. I phoned Apple and asked if there is a restocking fee for the UK (there isn't) and I am allowed to play with it and see how it all goes. It seems like there is more and more evidence for a refresh, and I asked if the refresh happens on the 10th August (one day outside my 14 days) would I be able to return it. The lady said that it should be possible.
On opening the iMac there were a few notes I made:
The security seal was broken, and the thin wrapping around the screen had it's sticker torn apart, signalling perhaps that the iMac has been opened before. This disappointed me a bit, although I guess I'm doing the same thing. The batteries were already in the mouse and keyboard, and I didn't have to install the software, which was very odd. The build number is CK01600..etc - it was apparently made in Cork, Ireland between 17th and 23rd April 2000. Yes, apparently this iMac was built in the year 2000! I'm guessing the year is wrong, but the fact
I just ordered and got an April built iMac is a little weird, no? Makes me think they picked a refurb by accident in the warehouse?
All this aside, I think that the 27" screen is for me, it's nice and big and there's loads of workspace. I have noticed the very very slightest yellowing towards the bottom, but I honestly don't think I would have noticed unless I checked these forums beforehand and heard about the problem. I also checked for dead/stuck pixels using this site:
http://imac.squeaked.com/test.php and I think that there is only 1 towards the bottom left of the screen (it is not a specific colour, just kinda shimmery).
Thanks for all the advice guys!