Upload & Sell: Off
Ian, I understand the attraction of an all-in-one such as an iMac: it has a very small footprint and is good for locations where space it tight. However, it also has some drawbacks as well. In my mind, the biggest drawback is that everything is in one package. If the motherboard dies, or the computer becomes obsolete, you're left with an unusable monitor. I'm on my third computer using the same monitor.
Secondly, most all-in-ones (and I believe this is especially true of the iMacs) have very limited expansion room. If you want to add a second (or third) hard drive (I have 4 in my tower), you have to use externals because there is no, or limited, expansion room. Once you start cluttering the desk with external hard drives (not to mention the additional fan noise), I'm not sure how much space you've saved. Also, most all-in-ones run hotter than a mid-tower (not as much space for ventilation), which likely somewhat shortens the life of the computer's components.