Yep it is my first mac. And I'm loving it. I think I'll need to upgrade the memory. 1 gb is a bit too less for even 'normal' use. I have like mail, browser, azureus, itunes, vlc running at the same time. I ran joost and then ran out of memory almost (i had like 80 mb of free memory). I was checking the memory usage and as expected when you run a lot of apps, it becomes slower because of the use of swap space.
I didn't return it anyways. I thought I was being too picky. Sure there are some dust particles but if you aren't looking for it you wont probably notice it. It's a huge machine that I don't want to carry back n forth between apple store and my place.
A thing that I noticed is the temperature of the machine. I noticed the following temperatures:
CPU A - 43
GPU - 55
Airport Card - 63
Power supply - 64
HD Bay 1 - 55
HD Macintosh - 58
Memory Controller - 49
Optical Drive - 48
(in degree celsius).
I found the side to be fairly warm but the top gets hot. Those who own the 24 incher, can you guys tell me if these temperatures are normal ? I know of smc fan control application that can be used to increase the speed. But I'm not very interested in tweaking the fan speeds if the temperature is ok.
Since you have 0 dead pixels on the LCD, I personally would not return it.
The front glass can be lifted off with a suction cup (I think) and cleaned if you were so inclined. Google iMac disassembly for this.
Congrats on your new machine! Is this your first Mac?