I'm going to buy an iMac but I'm torn between the two size options. The 21.5" is very tempting but the lack of an SSD/Flash-only option on this one is off-putting. The mid-2011 model I bought in (surprise surprise) mid-2011 suffered from the dreaded HDD hum/vibration/resonation problem that many seemed to get, and I had no choice but to return it. I notice that there's a Fusion drive option, but it's still essentially a HDD. The 27" with the 768Gb flash drive seems a good choice, except that I'd need to sell half my internal organs to be able to afford it. But no mechanical drive means my ears would love it. Do the smaller, slower HDDs in the latest 21.5" refresh solve the vibration problems or are users still experiencing this? My priority is silence. If I have to spend the extra (and it's a lot of extra) for a non-HDD option, then I guess I'm stuck with the 27" option, though I can't help but feel that's a bit overkill. Then again, my ears and my sanity would love it. I'm almost entirely new to iMacs and OS X too, so I have no real idea of what I'll end up using it for most. I know the 27" is geared more towards the 'serious' user, but I've been using a 26" monitor on my PC for years so the size wouldn't daunt me too much even if I was just surfing and playing the odd game. However, having owned a 21.5" previously for a short amount of time, I loved the 'compactness' (apologies for made up word), and found the 1920x1080 resolution more than adequate. 2560x1440? I'm wondering whether this is a bit too much. But if the HDDs are still vibrating, I guess I have no option but to go big. I realise that for most users humming/vibration isn't a big issue, but I'm blessed with a pair of very highly tuned ears that can hear a mouse sneezing from a mile away. Thanks in advance.